Installation & Operation Manual 6060 MODBUS PROTOCOL. This manual is a supplement to the 6060 Full Installation & Operation Manual PK514

Transcription

1 Installation & Operation Manual 6060 MODBUS PROTOCOL This manual is a supplement to the 6060 Full Installation & Operation Manual PK514 PK July

2 Explanation of Symbols: General Information Caution: ESD-Sensitive Components General Warning MODBUS is a registered trademark of the MODBUS-IDA Organization 2

3 Table of Contents 1. General Referenes Commissioning the interfae Mounting hints Eletrial onnetions RS 485 version (two-wire ) RS 422 version (four-wire - RS 485) Cable installation Sreening Terminating resistors Installation notes Bus settings Bus address Transmission parameters Master operation (MASt) System layout Minimum onfiguration of a MODBUS installation Maximum onfiguration of a MODBUS installation Wiring inside buildings Bus Protool Composition of a transmission byte General message frame CRC End of frame detetion Transmission priniples Response delay (dely) Modem operation (C.dEL) Funtion odes Reading several values Writing a single value Writing several values Error reord Error odes Diagnosis Return transmission of the reeived message (0x00) Restart of ommuniation (terminates the Listen Only mode) (0x01) Return transmission of the diagnosis register (0x02) Change to the Listen Only mode (0x04) Delete the ounter and reset the diagnosis register (0x0A) Return transmission of the message ounter (0x0B) Return transmission of the ounter for faulty message transmissions Return transmission of the ounter for messages with error ode Return transmission of the message ounter for this slave Return transmission of the ounter for unanswered messages

4 Return transmission of the ounter for messages answered with NAK Return transmission of the ounter for messages answered with Busy Return transmission of the parity error ounter Return transmission of the framing error ounter Return transmission of the ounter for too long messages MODBUS addresses, address areas, and address formats Area definitions Speial values Composition of the address tables Internal data types Index Address tables

5 1. General This doument desribes the implementation and operation of the MODBUS interfae used with the industrial ontroller 6060 whih will be alled devie in the rest of this doument. Devies with a MODBUS interfae permit the transmission of proess data, parameters, and onfiguration data. Eletrial onnetions are made at the base of the devie in the hannel of the top-hat DIN rail. The serial ommuniation interfae provides a simple link to superordinate PLCs, visualization tools, et. An additional interfae that is always fitted in the devie s front panel is the CommPort (PC) interfae. This interfae is not bussable, and serves for a diret onnetion with the ChromaloxPro software pakage that runs on a PC or laptop. Communiation is done aording to the master/slave priniple. The devie is always operated as a slave. The most important harateristis and physial/eletrial properties of the bus onnetion are: Network Topology linear bus, possible with bus termination at both ends (see below). Transmission Media sreened and twisted 2-wire opper leads Lead Lengths (without repeater) A maximum lead length of 1000 m should not be exeeded. Transmission Speeds The following transmission speeds are supported: bits/s Physial Interfae RS 485 with bus onnetions in the top-hat rail; onnetions made on site. Address range (32 devies in one segment. Expandable to 247 with repeaters.) 1.1 Referenes Further information on the MODBUS-Protool: [1] MODBUS Speifiations MODBUS appliation Protool Speifiation V1,1 MODBUS over serial line speifiation and implementation guide V1.1 Further information on RS 485: [2] ANSI/TIA/EIA-485-A 5

6 2. Commissioning the Interfae Instrument field bus onnetion is via the pins of onnetor B on the rear, via flat-pin onnetors or via srew terminals dependent on version. Constrution of suitable ables must be done by the user. 2.1 Mounting Hints If possible, the plae of installation should be exempt of vibration, aggressive media (e.g. aid, lye), liquid, dust or aerosol. The unit may be operated only in environments for whih it is suitable due to its protetion type. The housing ventilation slots must not be overed. In plants where transient voltage peaks are suseptible to our, the instruments must be equipped with additional protetive filters or voltage limiters! Caution! The instrument ontains eletrostatially sensitive omponents. Please, follow the instrutions given in the safety hints. 2.2 Eletrial Connetions The eletrial onnetion of the interfae an be done as two-wire RS 485, as well as four-wire RS 485 (often alled RS 422) RS 485 Version (Two-Wire ) The bus is build as RS two-wire able with ommon ground main. All the partiipants of an RS 485 bus are onneted in parallel to the signals Data A and Data B. The meaning of the data line terms are defined in the unit as follows: for signal 1 (off) Data A is positive to Data B for signal 0 (on) Data A is negative to Data B The terms Data A and Data B are reverse to A and B defined in [2]. For the purpose of limiting ground urrent loops, signal ground (GND) an be grounded at one point via a resistor RGND (100 ohms, 1/4 watt). 6

7 Assoiation of terms for the two-wire-modbus definition aording to [1]: Definition MODBUS D1 D0 Common Aording to Unit Data A Data B RGND Notes: 1. Terminating resistors between Data A and B at the able ends (see figure 2 on page 8) 2. Sreening (see figure 2 on page 8) 3. GND lead (see Fig. 6) Signal Terminal Option 3 Position TXD-B 19 TXD-A 17 GDN 18 Option A Position TXD-B 20 TXD-A 22 GDN 21 The following able onnetion methods are possible. 12 RXD-B 13 GND 19/20 17/22 18/21 14RXD-A 15 TXD-B (16) 17TXD-A DATA+ 1 DATA- TX+ TX- RX+ RX- (R)+Vs (B)GND 10 Figure 2 7

8 2.2.3 Cable installation Depending on eah appliation, suitable ables are to be used for the bus. When installing the ables, all relevant regulations and safety odes (e.g. VDE 0100) must be observed: Cable runs inside buildings (inside and outside of ontrol abinets) Cable runs outside buildings Potential balaning ondutors Sreening of ables Measures against eletrial interferene Length of spur lines In partiular, the following points must be onsidered: The RS 485 bus tehnology used here permits up to 32 devies in a segment to be onneted to one bus able. Several segments an be oupled by means of repeaters. The bus topology is to be designed as a line with up to 1000 m length per segment. Extensions by means of repeaters are permitted. The bus able is to be taken from devie to devie (daisy haining), i.e. not star onneted. If possible, spur lines should be avoided, in order to prevent refletions and the assoiated disturbanes in ommuniation. The general notes on interferene-free wiring of signal and bus leads are to be observed (see Operating notes EMC General information ( )). To inrease signal transmission reliability, we reommend using sreened, twisted pairs for the bus leads Sreening The type of sreening is determined primarily by the nature of the expeted interferene. For the suppression of eletrial fields, one end of the sreened able must be grounded. This should always be done as the first measure. Interferene due to alternating magneti fields an only be suppressed, if the sreened able is grounded at both ends. However, this an lead to ground urrent earth loops: galvani disturbane along the referene potential lead an interfere with the useful signal, and the sreening effet is redued. If several devies are linked to a single bus, the sreen must be onneted at eah devie, e.g. by means of sreen lamps. The bus sreen must be onneted to a entral PE point, using short, low-impedane onnetions with a large surfae, e.g. by means of sreen lamps Terminating Resistors The widespread US Standard EIA RS 485 reommends fitting terminating resistors at eah end of the bus able. Terminating resistors usually have a value of approx. 120 ohms, and are onneted in parallel between the data lines A and B (depending on the able impedane; for details, see the able manufaturer s data sheet). Their purpose is to eliminate refletions at the end of the leads, thus obtaining a good transmission quality. Termination beomes more important, the higher the transmission speed is, and the longer the bus leads are. However, if no signals are applied to the bus, it must be ensured that the signal levels are learly defined. This done by means of pull-up and pull-down resistors between +5V or GND, and the drivers. Together with the bus terminating resistor, this forms a voltage divider. Moreover, it must be ensured that there is a voltage differene of at least ±200mV between the data lines A and B, as seen by the reeiver. Normally, an external voltage soure is provided. 8

9 Fig. 6 shows the devie onnetions as reommended by the MODBUS User Organization [1]. Master 5V Pull Up LT D1 D0 LT Pull Down Commom Slave Slave Slave Figure 3: Reommended Connetions With four-wire onnetion (RS 422), eah wire pair orresponds to the drawing above. If no external voltage soure is available, and if there are only a few partiipants on the bus (e.g. only a master and a slave devie), and the transmission speed is low (e.g bits/s), the lead lengths are short, and terminating resistors have been fitted, it is possible that the minimum signal level annot be reahed. This will ause disturbanes in signal transmission. Therefore, if only a few PMA devies are onneted, we reommend the following proedure before fitting terminating resistors: Baud Rate Lead Length No. of PMA Devies Terminating Resistor 9600 Bist/s 1000 m < 8 no Bit/s 500 m < 8 no Bit/s 250 m < 8 no beliebig 8 useful other ases: try out If less than 8 PMA devies are onneted to a bus with the above maximum lead lengths, no terminating resistors should be fitted. Note: If additional devies from other manufaturers are onneted to the bus, no general reommendations are possible this means: trial and error! 9

10 2.2.6 Installation Notes Measurement and data leads should be kept separate from ontrol leads and power ables. Twisted and sreened ables should be used to onnet sensor. The sreen must be grounded. Conneted ontators, relays, motors, et. should be fitted with RC snubber iruits in aordane with manufaturer speifiations. The devie must not be installed near powerful eletrial or eletromagneti fields. - The devie is not ertified for installation in explosion-hazarded areas. - Inorret eletrial onnetions an result in severe damage to the devie. - Please observe all safety instrutions. 2.3 Bus Settings Bus Address The partiipant address of a devie onneted to a bus must be adjusted by one of the following means: the Engineering Tool ChromaloxPro using the menu item Othr/Addr or via the devie s front panel (see below) Ù 3s 1199 PArA Figure 4: Setting a Bus Address Ì 1199 ConF Ù 1199 n * Cntr Ì 1199 othr Ù 1199 baud Ù 1199 Addr Ì Ì Every devie onneted to a bus must have a different, unique address. Please regard: When alloating the unit s addresses don t give the same address to two units. In this ase a strange behavior of the whole bus beomes possible and the busmaster will not be able to ommuniate with the onneted slave-units. 10

11 2.3.2 Transmission parameters The transmission parameters of all devies linked to a bus must have the same settings. Baudrate (baud) The baudrate is the measure of data transmission speed. The devies support the following transmission speeds: bits/s bits/s 9600 bits/s 4800 bits/s 2400 bits/s Parity / Stop bit (PrtY) The parity bit is used to hek whether an individual fault has ourred within a byte during transmission. The devie supports: even parity odd parity no parity With even parity, the parity bit is adjusted so that the sum of the set bits in the 8 data bits and the parity bit result in an even number. Conversely, the same applies for uneven parity. If a parity error is deteted upon reeipt of a message, the reeiving devie will not generate an answer. Other parameters are: 8 data bits 1 start bit 1 stop bit 1 or 2 stop bits an be seleted when adjusting no parity. The max. length of a message may not exeed 256 bytes. 11

12 2.4 Master Operation (MASt) The 6060 master funtion is limited to broadast messages (data transmission to all onneted slaves). For operation as a master, the instrument must be onfigured aordingly by means of ChromaloxPro (engineering software for 6060). Figure 5: Master Funtion Parameter Setting A possible MODBUS master onfiguration is given in the drawing shown above. In this example, the atual master set-point (soure address 3170) is transmitted to the slaves (target address 3180) at intervals of 5 seonds. Figure 6: Example 12

13 2.5 System Layout Please observe the guidelines and notes provided by the manufaturer of the master devie regarding the layout of a ommuniation system Minimum onfiguration of a MODBUS installation A MODBUS installation onsists of not less than the following omponents: a bus master, whih ontrols the data traffi one or more slave partiipants, whih provide data upon demand by the master the transmission media, onsisting of the bus able and bus onnetors to link the individual partiipants, plus a bus segment (or several, whih are onneted by means of repeaters) Maximum onfiguration of a MODBUS installation A bus segment onsists of max. 32 field units (ative and passive). The greatest number of slave partiipants that an be operated by one MODBUS master via several segments, is determined by the internal memory struture of the master. Therefore, you should know the speifiations of the master when planning a MODBUS installation. The bus able an be opened at any point in order to add another partiipant by means of a bus onnetor. At the end of a segment, the bus able an be extended up to the total permissible length for a segment. The permissible length of a bus segment depends on the seleted transmission speed, whih in turn is determined mainly by plant layout (length of eah segment, distributed inputs/outputs) and the required san yles for individual partiipants. All partiipants onneted to the bus must be onfigured for the same transmission speed (bit rate). MODBUS devies must be onneted in a line struture. If more than 32 partiipants are required, or larger distanes than the permissible length of one segment are needed, the MODBUS installation an be extended by means of repeaters. Slave without terminating resistor Slave with terminating resistor Repeater without terminating resistor Repeater with terminating resistor Figure 7: Struture A fully onfigured MODBUS installation may ontain max. 247 partiipants with the address range Every installed repeater redues the max. number of partiipants with a segment. Repeaters are passive partiipants and do not require a MODBUS address. However, its input iruit represents an additional load in the segment due to the urrent onsumption of the bus driver. Nonetheless, a repeater has no influene on the total number of partiipants onneted to the bus. The maximum number of series-onneted repeaters an differ, depending on the manufaturer. Therefore, you should ask the manufaturer about possible limitations when planning a MODBUS installation. 13

14 2.5.3 Wiring Inside Buildings The following wiring hints apply for twisted-pair ables with sreen. The able sreen serves to improve overall eletromagneti ompatibility. Depending on requirements, the one or both ends of the able sreen must be onneted to a entral earth point (PE) by means of low-impedane onnetions with a large surfae, e.g. sreen lamps. When installing a repeater or field unit in a ontrol abinet, the able sreen should be onneted to an earth rail mounted as lose as possible to the able entry into the abinet. Rail in abinet at able gland The sreen must be taken right up to the field unit, where it is to be onneted to the ondutive housing and/or the metal onnetor. Hereby, it Funtion earth Cable sreening must be ensured that the devie housing (and possibly the ontrol abinet in whih the devie is installed), are held at equal ground potential by means of low-impedane onnetions with a large surfae. Conneting a Figure 8: Sreen Connetion sreen to a laquered or painted surfae is useless. By observing these measures, high-frequeny interferene will be grounded reliably via the able sreens. Should external interferene voltages still reah the data lines, the voltage potential will be raised symmetrially on both lines, so that in general, no destrutive voltage differenes an arise. Normally, a shift of the ground potential by several volts will not have an effet on reliable data transmission. If higher voltages are to be expeted, a potential balaning ondutor with a minimum ross-setion of 10 mm 2 should be installed parallel to the bus able, with onnetions to the referene ground of every field unit. In ase of extreme interferene, the bus able an be installed in a metal onduit or hannel. The onduit tube or the hannel must be earthed at regular distanes. The bus able must always be installed with a minimum separation of 20 m from other ables arrying voltages above 60 V. Similarly, the bus able must be run separately from telephone lines, as well as from ables leading into explosion-hazarded areas. In these ases, we reommend installing the bus able in a separate able tray or hannel. Cable trays or hannels should always be made of ondutive materials, and must be earthed at regular distanes. Bus ables should not be subjeted to any mehanial strains or obvious risks of damage. If this annot be ensured, suitable measures must be undertaken, suh as installation in onduit. Floating Installation: If the installation must be floating (no earth onnetion) for ertain reasons, the devie referene ground must only have a high-impedane onnetion to earth (e.g. an RC ombination). The system will then find its own earth potential. When onneting repeaters for the purpose of linking two bus segments, a floating installation is reommended, to prevent possible potential differenes being transferred from one segment to the next. 14

15 3. Bus Protool 3.1 Composition of a Transmission Byte Originally, the MODBUS protool was defined for the ommuniation between a supervisory system and the Modion PLC. It used a master/slave struture, in whih only one devie (master) is able to initiate data transations (queries). The query message from the master is answered (response) by other devies (slaves), whih supply the requested data. Moreover, the master an address a speifi slave via its MODBUS address, or address all onneted slaves by means of a general message (broadast). The MODBUS protool determines the transmission formats for the query and the response. Funtion odes define the ations to be exeuted by the slaves. Within the devie, the MODBUS protool uses the RTU (remote terminal unit) mode, i.e. every transmitted byte of a message ontains two hexadeimal haraters (0...9, A...F). The omposition of a byte in the RTU-protool is as follows: Start bit 8 data bits Parity/Stop bit Stop bit 3.2 General Message Frame The message is read into a data buffer with a defined maximum length. Longer messages are not aepted, i.e. the devie does not answer. The message onsist of the following elements: Devie address Funtion ode Data field CRC End of frame detetion 1 byte 1 byte N * 1 bytes 2 bytes Devie address (Addr) The devie address is used for identifiation. Devie addresses an be assigned in the range of The devie address 0 is reserved for Broadast messages to all slaves. A broadast message an be transmitted e.g. with a write instrution that is then exeuted by all the slaves on the bus. Beause all the slaves exeute the instrution, no response messages are generated. Funtion ode The funtion ode defines the transation type in a message. The MODBUS speifiation defines more than 17 different funtion odes. Supported odes are desribed in Setion 3.6. Funtion odes. Data field The data field ontains the detailed speifiations of the transation defined by the funtion ode. The length of the data field depends on the funtion ode. CRC As a further means of fault detetion (in addition to parity bit detetion) a 16-bit ylial redundany hek (CRC) is performed. The CRC ode ensures that ommuniation errors are deteted. For additional information, see Setion CRC. End of frame detetion The end of a message is defined by a period of 3,5 haraters, during whih no data transfer ours. For additional information, see Setion End of frame detetion Further information is given in the douments named in [1] or under 15

16 3.2.1 CRC The CRC is a 16-bit value that is attahed to the message. It serves to determine whether a transmitted message has been reeived without errors. Together with the parity hek, this should detet all possible ommuniation errors. If a parity fault is deteted during reading, no response message will be generated. The algorithm for generating a CRC is as follows: 1. Load CRC register with FFFFhex. 2. Exlusive OR the first transmit/reeive byte with the low-order byte of the CRC register, putting the result into the CRC register, zero-filling the MSB. 3. Shift the CRC register one bit to the right. 4. If the expelled bit is a 0 repeat step 3. If the expelled bit is a 1, exlusive OR the CRC register with value A001hex. 5. Repeat steps 3 and 4 for the other 7 data bits. 6. Repeat steps 2 to 5 for all further transmit/reeive bytes. 7. Attah the result of the CRC register to the message (low-order byte first, then the high-order byte). When heking a reeived message, the CRC register will return 0, when the message inluding the CRC is proessed End of Frame Detetion The end of a message (frame) is defined as a silene period of 3.5 haraters on the MODBUS. A slave may not start its response, and a master may not start a new transmission before this time has elapsed. However, the evaluation of a message may begin, if a silene period of more than 1.5 haraters ours on the MODBUS. But the response may not start before 3,5 haraters of silene. 3.3 Transmission Priniples Two transmission modes are used with MODBUS: Uniast mode Broadast mode In the Uniast mode, the master addresses an individual devie, whih proesses the reeived message and generates a response. The devie address an be Messages always onsist of a query (request) and an answer (response). If no response is read within a defined time, a timeout error is generated. In the Broadast mode, the master sends a write instrution (request) to all partiipants on the bus, but no responses are generated. The address 0 is reserved for broadast messages. 3.4 Response Delay (dely) Some devies require a ertain period to swith from transmit to reeive. The adjusted delay is added to the silent period of 3,5 haraters at the end of a message, before a response is generated. The delay is set in ms. 3.5 Modem Operation (C.dEL) The end of frame detetion of a reeived MODBUS message an be inreased by the period C.del. This time is needed e.g. for transmission via a modem, if messages annot be transmitted ontinuously (synhronous operation). The delay is set in ms. 16

17 3.6 Funtion Codes Funtion odes serve to exeute instrutions. The devie supports the following funtion odes: Funtion Code Hex Dez Desription Explanation 0x03 3 Read Holding (Output) Register Reading of proess data, parameters, and onfiguration data 0x04 4 Read Input Register Reading of proess data, parameters, and onfiguration data 0x06 6 Preset Single Register (Output) Wordwise writing of a value (proess value, parameter, or onfiguration data) 0x08 8 Diagnostis Reading the MODBUS diagnosti register 0x10 16 Preset Multiple Register (Output) Wordwise writing of several values (proess data, parameter or onfiguration data) The behavior of funtion odes 3 and 4 is idential. The following setions show various examples of message omposition Reading Several Values Messages with funtion odes 3 or 4 are used for (wordwise) reading of proess data, parameters or onfiguration data. For reading Float type data, 2 values must be requested for eah datum. The omposition of a read message is as follows: Request: Field Name Value (Hex) Explanation Address 11 Address 17 Funtion 03 or 04 Reading proess data, parameters or onfiguration data Start address High 02 Starting address 650 Start address Low 8A Reading the MODBUS diagnosti register No. of values 00 2 datums (2 words) 02 CRC CRC-Byte1 CRC-Byte2 Response: Field Name Value (Hex) Explanation Address 11 Address 17 Funtion 03 or 04 Reading proess data, parameters or onfiguration data No. of bytes 04 4 data bytes are transmitted Word 1 00 DE Word D CRC CRC-Byte1 CRC-Byte2 Proess data, parameters or onfiguration data. Address 650= 222 Proess data, parameters or onfiguration data. Address 651= 333 A broadast message is not possible for funtion odes 3 and 4. If the first addressed value is not defined, an error message ILLEGAL DATA ADDRESS is generated. If no further data are defined in the areas to be read following the first value, these areas will be entered with the value NOT DEFINED VALUE. This enables areas with gaps to be to be read in a message. 17

18 3.6.2 Writing a Single Value Messages with funtion ode 6 are used for (wordwise) writing of proess data, parameters or onfiguration data as integers. This funtion is not suitable for writing Float type data. The omposition of a write message is as follows: Request: Field Name Value (Hex) Explanation Address 11 Address 17 Funtion 06 Writing a single value (proess data, parameter or onfiguration) Write address High 02 Write address 650 Write address Low 8A Value 00 Preset value = 123 7B CRC CRC-Byte1 CRC-Byte2 Response: Field Name Value (Hex) Explanation Address 11 Address 17 Funtion 06 Writing a single datum (proess data, parameter or onfiguration) Write address High 02 Write address 650 Write address Low 8A Value 00 Preset value = 123 7B CRC CRC-Byte1 CRC-Byte2 If everything is orret, the response message orresponds exatly to the default. The devies an also reeive this message as a broadast with the address 0. A default value in the Real data format is not possible, as only 2 bytes an be transmitted as value. If a value is outside the adjustable range, the error message ILLEGAL DATA VALUE is generated. The datum remains unhanged. Also if the datum annot be written (e.g. onfiguration data, and the devie is online), an error message ILLEGAL DATA VALUE is generated. 18

19 3.7 Writing Several Values Messages with funtion ode 16 are used for (wordwise) writing of proess data, parameters or onfiguration data. For writing Float type data, 2 values must be transmitted for eah datum. The omposition of a write message is as follows: Request: Field Name Value (Hex) Explanation Address 11 Address 17 Funtion 10 Writing several proess values, parameters or onfiguration data Start address High 02 Write address 650 Start address Low 8A No. of values 00 2 values 02 No. of bytes 04 4 data bytes are transmitted Word 1 00 DE Word D CRC CRC-byte1 CRC-byte2 Response: Proess value, parameters or onfiguration data. Address 650 = 222 Proess value, parameters or onfiguration data. Address 651 = 333 Field Name Value (Hex) Explanation Address 11 Address 17 Funtion 10 Writing several proess values, parameters or onfiguration data Start address High 02 Write address 650 Start address Low 8A No. of values 00 2 proess values, parameters or onfiguration data 02 CRC CRC-byte1 CRC-byte2 The devies an also reeive this message as a broadast with the address 0. If the first value is not defined, an error message ILLEGAL DATA ADDRESS is generated. If the first value annot be written (e.g. onfiguration data, and the devie is online), an error message ILLEGAL DATA VALUE is generated. If no further data are defined or annot be written in the speified areas following the first value, these areas will be skipped. The data in these loations remains unhanged. This enables areas with gaps, or that are urrently not writable, to be hanged with a message. No error message is generated. If a value is outside the adjustable range, the error message ILLEGAL DATA VALUE is generated. Subsequent data are not evaluated. Previously aepted orret data are ative. 19

20 3.8 Error Reord An error reord is generated, if a message is reeived orretly, but message interpretation or the modifiation of a datum is not possible. If a transmission error is deteted, no response is generated. The master must retransmit the message. Deteted transmission errors are: Parity fault Framing error (no stop bit reeived) Overrun error (reeiving buffer has overflowed or data ould not be retrieved quikly enough from the UART) CRC error The omposition of the error reord is as follows: Field Name Value Explanation Address 11 Address 17 Funtion 90 Error reord for message Writing several parameters or onfiguration data. Composition: 80hex + funtion ode Error ode 02 ILLEGAL DATA ADDRESS CRC CRC byte1 CRC byte2 In the Funtion field, the most signifiant bit is set. The error ode is transmitted in the subsequent byte Error Codes The following error odes are defined: Code Name Explanation 01 ILLEGAL FUNCTION The reeived funtion ode is not defined in the devie. 02 ILLEGAL DATA ADDRESS The reeived address is not defined in the devie, or the value may not be written (read only). If several data are read simultaneously (funtion odes 01, 03, 04) or written simultaneously (funtion odes 0F, 10), this error is only generated if the first datum is not defined. 03 ILLEGAL DATA VALUE The reeived value is outside the adjusted limits or it annot be written at present (devie is not in the onfiguration mode). If several data are written simultaneously (funtion odes 0F, 10), this error is only generated if the first datum annot be written. 04 SLAVE DEVICE FAILURE More values are requested than permitted by the transmission buffer. Other error odes speified in the MODBUS protool are not supported. 20

21 3.9 Diagnosis By means of the diagnosis message, the devie an be prompted to send hek messages, go into operational states, output ounter values or to reset the ounters. This message an never be sent as a broadast message. The following funtions have been defined: Code 0x00 0x01 0x02 0x04 0x0A 0x0B 0x0C 0x0D 0x0E 0x0F 0x10 0x11 0x12 0x40 0x41 0x42 Explanation Return transmission of the reeived message Restart of ommuniation (terminates the Listen Only mode) Return transmission of the diagnosis register Change to the Listen Only mode Delete the ounter and reset the diagnosis register Return transmission of the message ounter (all messages on the bus) Reset of the ounter for faulty message transmissions to this slave (parity or CRC error) Return transmission of the ounter for messages answered with error ode Return transmission of the message ounter for this slave Return transmission of the ounter for unanswered messages Return transmission of the ounter for messages answered with NAK Return transmission of the ounter for messages answered with Busy Return transmission of the ounter for too long messages Return transmission of the parity error ounter Return transmission of the framing error ounter (stop bit not deteted) Return transmission of the ounter for full buffer (message longer than reeiving buffer) Request in the Integer format: If the setting for Integer with deimals (most signifiant 3 bits) is used for the address, the ounter ontents will be transmitted in aordane with the neessary onversion fator. Request in the Float format: If the setting for Float (most signifiant 3 bits are 010) is used for the address, the ounter ontents will betransmitted in the IEEE format. The largest value is 65535, beause the ounters in the devie are designed as word ounters. In the Float format, a 4-byte data field is returned with a request for ounter ontents. In all other ases, a 2-byte data field is returned. When swithing into the Listen mode (0x04) and at restart after the devie has hanged into the Listen mode, no response is generated. If a restart diagnosis message is reeived while the devie is not in the Listen mode, the devie generates a response. A diagnosis message is omposed as follows: Request: Field Name Value Explanation Address 11 Address 17 Funtion 08 Diagnosis message Sub-funtion High 00 Sub-funtion ode Sub-funtion Low YY Data field Byte 1 Further data definitions Byte 2 CRC CRC byte1 CRC byte2 21

22 3.9.1 Return Transmission of the Reeived Message (0x00) The message serves as a hek whether ommuniation is operational. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field Bytes of any ontent Return transmission of the reeived datum Restart of Communiation (Terminates the Listen Only Mode) (0x01) The slave is instruted to initialize its interfae, and to delete the event ounters. In addition, the devie is instruted to exit the Listen Only mode. If the devie already is in the Listen Only mode, no response is generated. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field Return Transmission of the Diagnosis Register (0x02) The slave sends its 16-bit diagnosis register to the master. The data ontained in this register are freely definable. For example, the information ould be: EEPROM faulty, LED defetive, et. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field Contents of the diagnosis register Change to the Listen Only Mode (0x04) The slave is instruted not to exeute or answer any messages addressed to it. The devie an only return to normal operation by means of the diagnosis message Sub-funtion or by means of a new power up. The funtion serves to disable a module that is behaving erratially on the MODBUS, so that the bus an ontinue operations. The devie does not generate a response after reeiving this message. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field No response Delete the Counter and Reset the Diagnosis Register (0x0A) The slave is instruted to delete the ontents of its event ounter and to reset the diagnosis register. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field 00 0A Return Transmission of the Message Counter (0x0B) The slave is instruted to return the value of its message ounter. The ounter ontains the sum of all messages, whih the slave has reorded on the bus. This ount inludes all the messages transmitted by the master and the other slaves. The ount does not inlude the response messages of this slave. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field 00 0B Message Counter 22

23 3.9.7 Return Transmission of the Counter for Faulty Message Transmissions The slave is instruted to return the value of its ounter for faulty message transmissions. The ounter ontains the sum of all messages addressed to the slave, in whih an error was deteted. Hereby, the faults an be CRC or parity errors. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field 00 0C Contents of ounter for faulty message transmissions Return Transmission of the Counter for Messages with Error Code The slave is instruted to return the value of its ounter for the messages answered with error ode. The ounter ontains the sum of all messages addressed to the slave, and whih were answered with an error ode. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field 00 0D Contents of ounter for message answered with error ode Return Transmission of the Message Counter for this Slave The slave is instruted to return the value of its ounter for messages to this slave. The ounter ontains the sum of all messages addressed to the slave. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field 00 0E Contents of ounter for messages addressed to this slave Return Transmission of the Counter for Unanswered Messages The slave is instruted to return the value of its ounter for unanswered messages. The ounter ontains the sum of all messages addressed to the slave, whih were not answered beause of internal events or deteted errors.. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field 00 0F Contents of ounter for unanswered messages Return Transmission of the Counter for Messages answered with NAK The slave is instruted to return the value of its ounter for unanswered messages. The ounter ontains the sum of all messages addressed to the slave, whih were not answered beause of internal events or deteted errors. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field 00 0F Contents of ounter for unanswered messages 23

24 Return Transmission of the Counter for Messages Answered with Busy The slave is instruted to return the value of its ounter for messages answered with Busy. The ounter ontains the sum of all messages addressed to the slave, whih were answered with Busy. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field Contents of ounter for messages answered with Busy Return Transmission of the Parity Error Counter The slave is instruted to return the value of its ounter for parity errors. The ounter ontains the sum of all messages addressed to the slave, in whih a parity error was deteted. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field Contents of ounter for the number of parity errors Return Transmission of the Framing Error Counter The slave is instruted to return the value of its ounter for the number of framing errors. The ounter ontains the sum of all messages addressed to the slave, in whih a framing error was deteted. A framing error ours, if the stop bit at the end of a byte is not deteted. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field Contents of ounter for the number of framing errors Return Transmission of the Counter for too Long Messages The slave is instruted to return the value of its ounter for too long messages. The ounter ontains the sum of all messages addressed to the slave, whih aused an overflow of the reeiving buffer, or if the data were not retrieved from the UART quikly enough. Definition of the reeived and returned data: Sub-Funtion Reeived Data Field Transmitted Data Field Counter for too long messages 24

25 4. MODBUS Addresses, Address Areas & Address Formats 4.1 Area Definitions The address is oded in 2 bytes. The most signifiant 3 bits determine the data transmission format. The following formats are available for rail line devies: Integer Integer with 1 deimal (Float a. to IEEE) Address area Smallest Largest Transferable Transferable hex dez. Data Transfer Format Value Value Resolution 0x x1FFF Integer without deimals /- 1 0x x3FFF Integer with 1 deimal / x x7FFF Float (IEEE format) -1.0 E E+037 +/-1.4E-045 For integer numbers with and without deimals, the value range to is transmitted via the interfae. Saling with the fator 1 or 10 must be arried out by the transmitting devie as well as by the reeiving devie. - Values are transmitted in the Motorola format (big endian).. - The relevant areas are grouped for proess data, parameter and onfiguration data reading and wring. - Multiple definition of proess data in different groups is possible. 4.2 Speial values The following speial values are defined for transmission in the integer format: Sensor fault This value is returned for data that do not represent a meaningful value due to a sensor fault Swith-off value The funtion is disabled Undefined value The devie returns this value, if a datum is not defined within the requested range ( NOT DEFINED VALUE ) Corresponds to 0x8000 hex. The value to be transmitted lies outside the transferable integer value range. The following speial values are defined for transmission in the Float format: -1.5E37 This datum is not defined. The devie returns this value, if a datum is not defined within the requested range. 25

26 4.3 Composition of the Address Tables In the address tables shown in Setion 5, the addresses for every parameter of the orresponding data format are speified in deimal values. The tables are strutured as follows: Name R/W Address Integer Real Type Value/off Desription base Name Desription of the datum R/ permitted type of aess: R = read, W = write Address integer Address for integer values base Integer without deimals 1 dp Integer with 1 deimal Real Floating point number / Float (IEEE format) Type internal data type Value/off permissible value range, swith-off value available Desription Explanations 4.4 Internal Data Types The following data types are assigned to data used in the devie: Float Floating point number Value range: , 0, INT Positive whole integer number Value range: Exeption: Swith-off value Text Text string onsisting of n haraters, urrently defined n = 5 Permissible haraters: 20H...7FH Long Positive whole Long number Value range: Enum Seletion value 26

27 5. Index A address areas address formats address tables addressing...5 area definitions...27 B Baudrate...13 broadast...17 broadast mode...18 bus address...13 bus protool bus segment...15 busprotool C able installation...11 able sreen...16 ommisioning the interfae omposition of the address tables...28 CRC D data...17 devie address...17 diagnosis E eletrial onnetions end of frame detetion...18 error odes...22 error reord...22 F format float...27 float a. to ieee...27 integer...27 Motorola...27 four-wire...9 funtion ode... 17, funtion odes G general message frame...17 I installation notes...13 internal data types...28 L lead length...5 M max. length...14 maximum onfiguration...15 modbus addresses modem operation...18 mounting...6 P parity error...14 R reading values...19 referenes...5 repeater...15 response delay...18 RS RS S Sreening...11 speial values...27 sensor fault...27 undefined value...27 stop bit...13 T terminating resistors...11 transmission byte...17 transmission format...27 two-wire...7 U uniast mode...18 W wiring...16 writing a value...20 writing several values

28 6. Address Tables The following setions desribe the address tables for: industrial ontroller

29 Code Table Table of Contents 1 Cntr Con... 1 PAr... 4 Signal InP.1 Con Par Signal InP.2 Con Par Signal InP.3 Con Par Signal Lim Con Par Signal Lim2 Con Par Lim3 Con Signal Par Signal LOGI Con Signal ohne Par Signal ohne1 Signal ohne2 Signal ohne3 Signal ohne4 Signal othr Con Signal Out.1 Con Signal Out.2 Con Signal Out.3 Con Signal Out.4 Con Signal Out.5 Con Signal Out.6 Con Signal PAr.2 Par ProG Con Par Signal SEtP Par Signal Tool Con

30 Code Table 1 Cntr ConF Name r/w Adr. Integer Real Typ Value/Off Desription SP.Fn r/w Base Enum Enum_SPFN Basi onfiguration for setpoint proessing, e.g. setpoint ontroller swithable to external setpoint. Configuration of speial, ontroller-dependent setpoint funtions. 0 Setpoint ontroller an be swithed over to external setpoint (->LOGI/SP.E) 1 Program ontroller for setpoint profile. The program profile is definable by the user. 2 Timer, operating mode 1 (bandwidth monitoring, swith-off at the end). After timer start, the ontroller lines out at the defined setpoint. The timer time (t.sp) runs when the proess value enters the adjusted band around the setpoint (x = SP ± b.ti). When the timer has elapsed, the ontroller is swithed to Y2 (= fixed positioning value) and the lower display alternates between 'End' and the setpoint. 3 Timer, operating mode 2 (bandwidth monitoring, pause at the end). After timer start, the ontroller lines out at the defined setpoint. The timer time ( t.sp) runs when the proess value enters the adjusted band around the setpoint (x = SP ± b.ti). When the timer has elapsed, the ontroller ontinues with setpoint SP, and the lower display alternates between End and the setpoint. 4 Timer, operating mode 3 (swith-off at the end). After timer start, the ontroller lines out at the defined setpoint. The timer time (t.sp) runs immediately after swith-over. When the timer has elapsed, the ontroller is swithed to Y2 (= fixed positioning value) and the lower display alternates between 'End' and the setpoint. 5 Timer, operating mode 4 (pause at the end). After timer start, the ontroller lines out at the defined setpoint. The timer time (t.sp) runs immediately after swith-over. When the timer has elapsed, the ontroller ontinues with setpoint SP, and the lower display alternates between 'End' and the setpoint. 6 Timer, operating mode 5 (delayed start). The timer starts immediately. The ontroller ontinues with Y2 (= fixes positioning value). When the timer (t.sp) has elapsed, the ontroller swithes over to the adjusted setpoint. 7 Timer, operating mode 6 (setpoint swith-over). After swithing over from SP to SP.2, the ontroller lines out at SP.2. The time (t.sp) runs when the proess value enters the adjusted band around the setpoint (x = SP ± b.ti). When the timer has elapsed, the ontroller swithes bak to setpoint SP, and the lower display alternates between 'End' and the setpoint. 10 Setpoint ontroller with start-up funtion. The start-up funtion is a protetive funtion, e.g. with hot runner ontrol. To prevent destrution of high-performane heating elements, they must be heated slowly to remove any humidity. With ativated start-up funtion, the ontroller maintains the redued starting temperature for a defined dwell period. Subsequently, the ontroller swithes over to the main setpoint. 11 Setpoint ontrollers are swithable to external setpoint and to a seond setpoint, always with the start-up funtion.the start-up funtion is a protetive funtion, e.g. with hot runner ontrol. To prevent destrution of high-performane heating elements, they must be heated slowly to remove any humidity. With ativated start-up funtion, the ontroller maintains the redued starting temperature for a defined dwell period. Subsequently, the ontroller swithes over to the main setpoint. 30

31 1 Cntr ConF Name r/w Adr. Integer Real Typ Value/Off Desription b.ti r/w Base C.Fn r/w Base man r/w Base Float Timer tolerane band for operating mode:1 (bandwidth monitoring with swith-off at the end)2 (bandwidth monitoring with pause at the end), and6 (setpoint swith over). The timer runs as long as the proess value is within the bandwidth limits (setpoint ± b.ti) Enum Enum_CFn Control behavior (algorithm) referred to output value: e.g. 2- or 3-point ontroller, signaller, 3-point stepping ontrol. 0 On/Off (2-point) ontroller or signaller with one output. The on/off ontroller or the signaller swithes its output when the proess value leaves the defined hysteresis band around the setpoint. 1 PID ontrol, e.g. heating, with one output: Swithed as a digital output (2-point) or used as an analog output (ontinuous). PID ontrollers respond quikly to hanges of the ontrol deviation, and typially do not exhibit any permanent ontrol offset. 2 D / Y / Off, or 2-point ontroller with partial/full load swith-over. 2 digital outputs: Y1 is the swithing output and Y2 is the hangeover ontat for D/Y. 3 2 x PID ontrol, e.g. heating/ooling. Two outputs: Swithed as a digital output (3-point) or used as an analog output (ontinuous). PID ontrollers respond quikly to hanges of the ontrol deviation, and typially do not exhibit any permanent ontrol offset. 4 3-point stepping ontroller, e.g. for motor atuators. Two digital outputs. No atuating pulses are generated when the proess is lined out. 7 3-point signaller. The 3-point signaller swithes two digital outputs, depending on their swithing differene (Sd1 and Sd2), the trigger point separation, and from the ontrol deviation. 8 3-point stepping ontroller that an be swithed over to signaller operation. Via interfae or front panel key (depending on onfiguration), the operating mode an be swithed between 3-point stepping ontroller and signaller (1 output). 9 3-point stepping ontroller an be swithed over to 3-point-signaller operation. Via interfae or front panel key (depending on onfiguration), the operating mode an be swithed between 3-point stepping ontroller and 3-point-signaller (2 outputs) Enum Enum_mAn Enables the output value to be adjusted in manual operation. If adjustment is not enabled, the output value annot be hanged in manual operation, neither with the front keys nor via the interfae. Note: This setting does not affet the auto/manual swithover funtion 0 The output value annot be hanged in manual operation, neither with the front keys nor via the interfae. 1 The output value is to be adjusted in manual operation (see also LOGI/mAn). 31