Model 3000 Fieldbus Transmitter

Transcription

1 Model 3000 Fieldbus Transmitter (for load cell based weighing systems) Installation & Operating Manual (Software Code PDT409 / Release 0.0) Modbus RTU / Profibus DP / DeviceNet Versions P.O. Box Farmington, NH Tel: cands_nh@msn.com 1

2 CONTENTS Main functions and technical features Page 3 Basic operating principal Page 4 Wiring Page 5 Load cell connections Page 6 Configuring the instrument Page 7 Installing the EasyCal Plus Software Page 7 Starting the EasyCal Plus Application Page 7 The main screen Page 7 The Configuration Panel Page 9 STEP 1: Programming the number of load cells Page 9 STEP 2: Data-sheet calibration Page 9 STEP 3: Programming the display division value Page 10 STEP 4: Programming the output rate Page 11 STEP 5: Dead-weight calibration Page 12 STEP 6: Programming the digital filter Page 13 STEP 7: Saving the configuration Page 14 Data recording into an MS Access File Page 15 Notes Page 17 The Modbus RTU Protocol Page 18 Communication parameters Page 18 List of supported functions Page 18 Response time Page 18 Errors in the received data Page 18 Warnings and other important information Page 19 Modbus functions - Communication strings details Page 21 List of the holding registers Page 22 The Profibus-DP protocol Page 25 Input Data Area Page 25 Output Data Area Page 27 The GSD File Page 28 Notes about the Profibus connection Page 30 Details about the Profibus module used on the E-Link 3000 (AnyBus-IC PDP) Page 31 Profibus-DP connector Page 31 The DeviceNet protocol Page 32 Input Data Area Page 32 Output Data Area Page 34 The EDS file Page 35 Details about the DeviceNet module used on the E-Link 3000 (AnyBus-IC DEV) Page 36 DeviceNet connector Page 36 2

3 Main Functions Converts the analog signal from the load cells into a communication protocol to a PC, PLC or DCS via fieldbus or Ethernet network. Configures the parameters from a PC with dedicated software or directly from the Master via the chosen communication protocol. Connects up to 4 load cells (2 minimum) Provides management, diagnosis and fault detection through individual mv/v load cell signals. Provides faulty load cell emulation (faulty load cell is excluded from the weighing system with automatic re-calibration based on the remaining load cells). Integrates easily into any industrial supervision and control system. Technical Features Operating Temperature + 14 to ºF (relative humidity: 85% non-condensing) Storage Temperature 4 to ºF Power Supply 12 to 24 Vdc Excitation Voltage 5 Vdc Number of load cells 2, 3 or 4 A/D Converter Characteristics 24 Bit - internal resolution > 16,000,000 counts - resolution at 2 mv/v > 3,000,000 counts on each load cell channel - input sensitivity µv/count - load cells signal input range 5.0 mv/v to mv/v - number of readings per 0.1 to 72 depending on the number of load cells and the digital second per load cell filter selection - linearity better than ± 0.01% of F.S. - thermal drift better than ± % of F.S./ C Serial Ports: - COM1 RS-232 (for configurating parameters from PC with EasyCal Plus configuration utility) - COM2 RS-485 with Modbus RTU protocol (Base model) (protocols available through the chosen Profibus-DP, DeviceNet, CANOpen, Modbus TCP over communication hardware) Ethernet Connections: - load cells 4 removable terminal blocks, 7-positions - power supply, RS-232 and RS removable terminal block, 7-positions - Profibus-DP 9 pin Sub-D connector - DeviceNet 1 removable terminal block, 5-positions - CANOpen 9 pin Sub-D connector - Modbus TCP over Ethernet RJ45 connector Dimensions (DIN rail mtg. enclosure) 5.12 x 3.94 x 2.36 (L x D x H) CE Conformity EN , EN

4 Basic operating principle The Model 3000 Fieldbus Transmitter offers a reliable way to transmit digital weight data (signals coming from traditional analog load cells) directly from the load cell installation site. The various hardware configurations allow the transmitter to easily integrate with those plants based on the most popular fieldbuses or on the Ethernet network. There are three different ways to configure the transmitters parameters: 1. With a PC over the RS-232 port using EasyCal Plus an MS Windows based program (included with unit). 2. Via the Modbus RTU protocol over the RS-485 port (units without fieldbus or Ethernet options). See page 18 for additional information. 3. Using one of the available fieldbus options (Profibus-DP, DeviceNet, CANOpen) or through the Ethernet option (with Modbus TCP protocol). Model

5 Wiring TB5 1 Model TB TB TB TB4 35 No. Terminal Block TB5 1 + Power supply (12 to 24 Vdc) 2 - Power supply 3 + RS RS RS-232 (Tx) 6 RS-232 (Rx) 7 RS-232 (Gnd) Cable length < 50 feet PC COM Port 9-pin Sub-D connector RS-232 (Rx) 2 RS-232 (Tx) 3 RS-232 (Gnd) 5 TB1 LOAD CELL # 1 8 Shield 9 - Excitation 10 + Excitation 11 + Sense 12 - Sense 13 - Signal 14 + Signal TB2 LOAD CELL # 2 15 Shield 16 - Excitation 17 + Excitation 18 + Sense 19 - Sense 20 - Signal 21 + Signal TB3 LOAD CELL # Signal 23 - Signal 24 - Sense 25 + Sense 26 + Excitation 27 - Excitation 28 Shield TB4 LOAD CELL # Signal 30 - Signal 31 - Sense 32 + Sense 33 + Excitation 34 - Excitation 35 Shield 5

6 Load cell connections The terminal blocks for the load cells have been designed to accept 6 wire load cells. See Figure 2. For load cells with 4 wires, the Excitation and Sense leads must be interconnected as shown in Figure 1. Load cell 1: terminals 8 to 14 (Terminal Block TB1) Load cell 2: terminals 15 to 21 (Terminal Block TB2) Load cell 2: terminals 22 to 28 (Terminal Block TB3) Load cell 2: terminals 29 to 35 (Terminal Block TB4) Figure 1: 4 wire load cell connection Load Cell # 1 Shield - Excitation + Excitation - Signal + Signal Model 3000 No. Terminal Block TB1 8 Shield 9 - Excitation 10 + Excitation 11 + Sense 12 - Sense 13 - Signal 14 + Signal Figure 2: 6 wire load cell connection Load Cell # 1 Shield - Excitation + Excitation + Sense - Sense - Signal + Signal Model 3000 No. Terminal Block TB1 8 Shield 9 - Excitation 10 + Excitation 11 + Sense 12 - Sense 13 - Signal 14 + Signal Connect the remaining load cells (2, 3 and 4) to terminal blocks TB2, TB3 and TB4 For weighing systems with only 2 load cells, Terminal blocks TB3 and TB4 are not used. For weighing systems with only 3 load cells, Terminal block TB4 is not used. NOTE: Be sure to identify each of the load cells by numbering them 1 to 4. 6

7 Configuring the instrument The Model 3000 Fieldbus Transmitters are normally configured and calibrated via a computer using EasyCal Plus an MS Windows based program supplied on a CD and included with each unit. The units can also be configured using one of the following 2 alternative modes: 1. Through the Modbus RTU protocol over the RS-485 port (available ONLY for those boards without fieldbus or Ethernet options). See page Through any of the fieldbus options available on the board (Profibus-DP, DeviceNet, CANOpen) or through the Ethernet option (with Modbus TCP protocol) Installing the configuration software Instead of installing the software directly from the CD, we recommend that you copy the files and paste them into a new folder on the PC, then start the installation process by double clicking on the setup icon. Follow the installation wizard until the procedure ends. Starting the application Establish a RS-232 serial connection with the PC, then apply power to the transmitter (See page 5). From Start My Programs select the EasyCal Plus utility software. A window for selecting which COM port is connected to the transmitter, will appear. The communication parameters are fixed at: bps, N, 8, 1 and CANNOT be modified. If the selected COM port is not available (not installed or is being used by another application), the Start button will remain disabled and a message Port not available will be displayed. The Main Screen The EasyCal Plus configuration utility allows the user to display and change the parameters of the transmitter that is currently connected to the PC over the RS-232 serial port. In addition, different views can be selected. 7

8 The main screen provides the following information: Application Version: PC application code. In case of problems we recommend that you provide this information when requesting technical assistance. Software Version: code of the software version that the Model 3000 Transmitter is running. LC Channels: number of load cell channels currently enabled LC Updates/Second: number of readings per second on each load cell channel Digital Filter: digital filter value Display Division: weight value increment size (minimum increment of the right end digit in the weight value reading) Profibus Address: PROFIBUS-DP slave node number (0 to 126) DeviceNet Address: DeviceNet slave node number (0 to 63) DeviceNet Baud Rate: DeviceNet network baud rate (125, 245 or 500 kbps) Protocol Addr: serial address of the board ( for the selected protocols, e.g. PROFIBUS-DP) Acquisition Delay: time delay between two data readings. Enter the new value and press Set New Delay. The time delay between two data readings is automatically stored in the delay.ini file. When the application is started again the delay.ini file contains the last programmed value. In the WEIGHT VIEW field (default) the individual weight values (1 to 4) are displayed. Each weight field can be: 1. Numeric value: weight value read by the load cell connected to the relative channel 2. O-L : the load cell channel is enabled, but the load cell is not connected The weight readings can be stored as a MS Access file: enter a name in the Table name for data field and click on the Save in Table button to start/stop logging. The following characters:,. ( ) - / \ can t be used in the Table name, if present they will be automatically erased by the application when the Save in Table button is clicked, and the name will be saved without them. The VIEW menu enables the user to switch among three different views of the Black fields: WEIGHT VIEW: INTERNAL COUNT VIEW: mv/v VIEW: All of the individual weight values are displayed. The Total field displays the sum of the individual weight values. All of the individual A/D converter internal counts are displayed. The Total field is disabled. All of the individual mv/v signals are displayed. The Total field is disabled. The User Manual can be accessed through the HELP menu (MS Windows 2000 and Windows XP only) 8

9 The Configuration Panel STEP 1: Programming the number of load cells (Set number of channels) There are six file folders on the lower half of the screen the 1st. one is used to select the number of load cell channels to be enabled. Click on the Set Ch. button to store the value into the transmitter. The displayed values will be updated according to the new setting. STEP 2: Data Sheet Calibration ( Data sheet Calib. ) The 2 nd file folder is used to program both the nominal capacity and sensitivity (rated output in mv/v) of each load cell, this data will be used by the transmitter to perform the Data sheet calibration (theoretical calibration) of each LC channel previously enabled on STEP 1. The data sheet calibration procedure allows the transmitter to be calibrated without a transducer simulator or test weights. This procedure is based on the capacity and certified, full scale mv/v output (sensitivity) of the LC s. As soon as the Set Cal. button is pressed all the parameters just entered will be stored in the transmitters memory and the Display division value will be programmed automatically. The transmitter is capable of counting by 1 s up to 60,000 counts however, for values greater than 100,000 the unit automatically selects a lower resolution to ensure better stability. In the weight readings, the display division represents the minimum increment of the least significant digit (LSD). Examples: If Capacity = 1,200, the display division takes a value of 0.02 automatically (1,200/60,000 = 0.02). If Capacity = 2,500, the display division takes a value of 0.05 automatically (2,500/60,000 = 0.041; this value will be rounded up to 0.05). If Capacity = 30,000, the display division takes a value of 0.5 automatically (30,000/60,000 = 0.5). However the user can modify the display division value according to their requirements, with respect to the maximum resolution that the transmitter is able to offer (600,000 counts over the capacity value). Using the above examples, the minimum display division value can be as follows: For Capacity 1,200: (1,200/600,000 = 0.002) For Capacity 2,500: (2,500/600,000 = ; rounded up to 0.005) For Capacity 30,000: 0.05 (30,000/600,000 = 0.05) 9

10 NOTE: use a. (decimal point) to separate integers from decimal digits when programming the mv/v values. The, (comma) character will automatically be replaced by a decimal point. STEP 3: Programming the Display Division value (Select Division) The 3 rd file folder is used to modify the display division value that was automatically entered. This setting must meet all of the requirements listed under STEP 2. Click on the Set Div. button to store the value into the transmitters memory. The displayed values will be updated based on the new setting. 10

11 STEP 4: Programming the number of readings on each LC channel (LC Updates/Second) The 4 th file folder is used to select the number of readings per second on each load cell channel. This parameter is affected by the number of load cell channels being used and the digital filter value. Table 1 shows the number of readings per second (Hz) of each available channel. Table 2 shows the resulting Output Rate. This data corresponds to a digital filter value of zero. Table 1 Selectable readings per second of each LC channel 2 Load Cell Channels 3 Load Cell Channels 4 Load Cell Channels 6 Hz 4 Hz 3 Hz 12 Hz 8 Hz 6 Hz 22 Hz 15 Hz 11 Hz 42 Hz 28 Hz 21 Hz 72 Hz 48 Hz 36 Hz Table 2 Resulting Output Rate A/D converter operating frequency 50 Hz 100 Hz 200 Hz 400 Hz 800 Hz Output Rate Note: The number of readings per second (Hz) on each channel is influenced by the action of the Digital Filter (this parameter can be set later at STEP 6). The Digital Filter value can range from 0 to 9; the higher the value the higher the filtering. The data in the above tables correspond to a digital filter value of zero (0 = Filter Off). Table 3 (see STEP 6) shows the actual number of readings per second based on the number of load cell channels being used and the filter setting. Once the output rate has been selected click on the Set Upd/Sec button to store the value into the transmitters memory. The displayed values will be updated based on the new setting. 11

12 STEP 5: Calibration with sample weight (Dead Weight Calibration). The 5 th file folder is used to perform the Dead Weight Calibration. Dead weight calibration involves the use of test weights for adjusting the Full Scale. Zero and Full Scale calibration are not interactive therefore the user can perform either the Zero or the Full Scale calibration independently. Dead Weight Calibration is NOT mandatory, it s only required for accuracies greater than what was already obtained automatically with the Data Sheet Calibration (STEP 2), otherwise STEP 5 can be omitted by clicking on another file folder. It is possible to perform only the Zero Calibration, the full scale calibration can be omitted by clicking on another file folder. To perform the Full Scale calibration a sample weight must be applied on the scale prior to proceeding, after which the user must enter the sample weight value in the FS Calibration box and click on the FS CALIBRATION button. The sample weight value to be entered can include decimal digits however a decimal point must be used to separate integers from decimal digits. NOTES: The ZERO calibration sets the weight to zero on ALL the LC channels SIMULTANEOUSLY. The FULL SCALE calibration APPLIES TO THE TOTAL weight value (sum of the individual weight values) which is displayed in the center box marked Total. ZERO and FULL SCALE calibration of INDIVIDUAL LC channels are NOT PROVIDED FOR. When performing a Full Scale calibration, the weight values automatically assigned to the individual load cell channels are NOT EVENLY DISTRIBUTED (Example: 25% with 4 load cells, 33,3% with 3 load cells or 50% with 2 load cells), but represent the actual weight distribution on each load cell. 12

13 STEP 6: Programming the Digital Filter value (Digital Filter) The 6 th file folder is used to program the digital filter that can be selected from the pop-up menu. The digital filter value can range from 0 (no filtering) to 9 (maximum filtering). Table 3 shows the actual number of readings per second (Hz) based on the number of load cell channels being used and the digital filter setting. Table 3 Actual number of readings per second of each load cell channel Digital Filter (2) Channels (3) Channels (4) Channels , A B C D E A B C D E A B C D E A/D converter operating Frequency (Hz) These values represent the frequency used by the A/D converter to poll the load cells. The A/D converter operating frequency cannot be edited, it is determined by the transmitter based upon: the number of active load cell channels, digital filter setting and number of readings per second. Once the digital filter value has been selected click on the Set Filter button to store the value into the transmitters memory. The displayed values will be updated according to the new settings. 13

14 STEP 7: Saving the configuration All the data previously programmed must be permanently stored in the transmitters memory by clicking on the Save Configuration button, a Configuration Saved message appears on the screen. Click on the OK button. END OF THE PROCEDURE 14

15 Data recording into an MS ACCESS file The SAVE IN TABLE button allows the user to start data logging for monitoring the weighing system within a given period of time. Data will be saved into an MS Access table, therefore a name must be entered in the MS Access Table name field prior to proceeding, otherwise the following message will appear: If the table name already exists, the following message will appear: Click on OK to overwrite the data in the existing table or click on Cancel to quit. To start data logging, click on the SAVE IN TABLE button. To stop data logging, click on the STOP SAVE IN TABLE button. The program logs approximately 5 to 14 weight values per second (both individual and total weight values) depending on the number of load cell channels, the digital filter value and the LC updates per second being used. The MS Access table will be saved (under the name of acquisition.mdb ) into the same directory containing the main application (by default C:\My Programs\PWIN30). 15

16 Double click on the acquisition.mdb icon to open MS ACCESS this allows the user to select which table must be displayed (in the following example table TestFile ). 16

17 Notes If the transmitter is disconnected from the PC while the application is running, the update of the displayed values stops and a TIMEOUT message will appear momentarily. When the transmitter is re-connected to the PC, the application usually resumes normal operation, but sometimes an irreversible error occurs since the serial connection is not controlled continuously. The application can also collect data through a USB to Serial Converter however, the communication speeds are reduced. 17

18 The Modbus RTU Protocol In its basic hardware configuration the Model 3000 Fieldbus Transmitter handles the data communication with a PC, PLC or DCS Master through the Modbus RTU protocol over the RS-485 serial port. The RS-485 serial port is available on terminals 3 (+) and 4 (-) of terminal block TB5 (see page 5). Communication Parameters Start bit 1 Data bits 8 [Least Significant Bit (LSB) sent as first bit] Parity No Stop bit 1 Baud rate 9600 List of supported functions Function Description 03 (03) READ HOLDING REGISTERS (Reading programmable registers) 06 (06) PRESET SINGLE REGISTER (Writing a single register) 16 (10) PRESET MULTIPLE REGISTERS (Writing multiple registers) Hexadecimal values between brackets Each function is composed of a Query (request from the host to the instrument) and a Response (answer from the instrument to the host). Queries and responses are composed of a sequence of data. See page 21 for a detailed explanation. Please note that the code 0x before any value indicates that the value is expressed as hexadecimal Response Time The response time for most data requests is within 20 milliseconds. Exceptions: (Max. response time = 550 msec): Load cell capacities Load cell sensitivities Zero Calibration Full Scale Calibration Digital Filter Load cell emulation Errors in the received data If the string is received correctly but is not executable, the slave answers the host with an EXCEPTION RESPONSE. The field function is transmitted having the most significant digit (MSD) set to 1. EXCEPTION RESPONSE Address Function Except. code 2 byte A Funct + 80h 0x01 CRC Description of the exception codes: Code Description 1 ILLEGAL FUNCTION (The function is not valid or not supported) 2 ILLEGAL DATA ADDRESS (The specified data address is not available) 3 ILLEGAL DATA VALUE (The data value received is not valid) 18

19 Warnings The Modbus protocol writes directly into the instruments memory. Use caution when sending data to the instrument: The data being sent must be within the specified ranges given in the tables on the following pages. Important information The TOTAL WEIGHT value is expressed as absolute value (in hexadecimal format) on a double word (Modbus word 0001 and 0002). Weight values up to are represented by the 2 bytes of the word Weight values greater than also involve the word 0001 Values greater than are shared in 2 parts: the most significant (MSW) that is represented by the 2 bytes of the word 0001, the least significant (LSW) that is represented by the 2 bytes of the word 0002, EXAMPLE # 1 MSW = Most Significant Word LSW = Least Significant Word The value 12345, expressed in hexadecimal format, corresponds to 2 bytes: 30 39; The 2 bytes (30 and 39) will be represented in the word 0002 only. Therefore: 00 in the 1 st byte of the word in the 2 nd byte of the word 0001 Decimal value = in the 1 st byte of the word in the 2 nd byte of the word 0002 Word 0001 Hexadecimal value corresponding to Bytes numbering in the 2 words EXAMPLE # 2 NOTE: The representation of values using a double word (MSW and LSW) as described above is known as a Long Unsigned Integer which complies with the Modbus RTU protocol standards The value , expressed in hexadecimal format, corresponds to 3 bytes: F4; The MSW will contain 00 07, while the LSW will contain 27 F4. Therefore: 00 in the 1 st byte of the word in the 2 nd byte of the word 0001 Decimal value = in the 1 st byte of the word 0002 F4 in the 2 nd byte of the word 0002 Word Hexadecimal value corresponding to F4 Bytes numbering in the 2 words

20 The INDIVIDUAL WEIGHT values (those detected by each load cell channel) are expressed as number of counts (in hexadecimal format) on a single word (Modbus words 0003 to 0006 for LC channels 1 to 4), therefore the host must also read the content of the word 0012 ( Display division ), then multiply thenumber of counts by the display division value in order to obtain the actual weight value. Example: If: Number of counts on LC channel 1 (word 0003) = Display division (word 0012) = 0.2 Actual weight value of LC channel 1: x 0.2 = 4696 The display division value is coded in hexadecimal format. The following table gives the correspondence between display division value and hex code: Content of the Modbus Word 0012 Hexadecimal Code Corresponding disp. div. value A 0B 0C 0D 0E 0F NOTES: For a detailed explanation of the Display Division parameter, please refer to STEP 2 on page 9. The addresses given in the following tables refer to the standards provided in the Modicon Modbus Protocol Reference Guide PI-MBUS-300 Internet: 20

21 Modbus Functions Communication strings (details) Symbols used in the strings: A = 1 byte for slave address (Example: Slave Nº 17: A = 0 x 11) FUNCTION 3: READ HOLDING REGISTERS QUERY Instrument serial Function 1st register Number of 2 byte address address registers A 0x03 0x0000 0x0002 CRC RESPONSE Instrument serial Function Nr. of bytes 1st register 2nd register 2 byte address value value A 0x03 0x04 0x0064 0x00C8 CRC FUNCTION 6: PRESET SINGLE REGISTER QUERY Instrument serial Function Register address Value 2 byte address A 0x06 0x0000 0x1234 CRC RESPONSE Instrument serial Function Register address Value 2 byte address A 0x06 0x0000 0x1234 CRC The response includes the echo of the query. FUNCTION 10: PRESET MULTIPLE REGISTERS QUERY Instrument serial Function 1st register Number of Nr. of 1st register 2nd register 2 byte address address registers bytes value value A 0x10 0x0000 0x0002 0x04 0x0000 0x0000 CRC RESPONSE Instrument serial Function 1st. register Number of 2 byte address address registers A 0x10 0x0000 0x0002 CRC Number of registers: Number of bytes: Registers value: Number of the registers to be written, starting from the 1st address. Number of bytes transmitted (2 bytes each register) Content of the registers. The response includes the identification of the modified registers. 21

22 LIST OF THE HOLDING REGISTERS (4xxxx) Modbus Word Variable Values or Ranges Min. Max. Read / Write 0000 Status Register 0, 1, 2, 4, 8, 10, 20 Read (1) Total weight value (MSW) Total weight value (LSW) Notes 0 - Total Capacity Read (2) 0003 Weight value LC channel LC 1 Capacity Read (3) 0004 Weight value LC channel LC 2 Capacity Read (3) 0005 Weight value LC channel LC 3 Capacity Read (3) 0006 Weight value LC channel LC 4 Capacity Read (3) 0007 Digital Filter 0-9 (**) Read / Write (4) 0008 LC s nominal sensitivity Read / Write (5) LC s Total capacity (MSW) LC s Total capacity (LSW) 0-Total Capacity Read / Write (6) 0011 Number of active LC channels 2, 3, 4 Read / Write 0012 Display division value 0-11 Read / Write (7) 0013 Load cells operating mode 0, 1, 2, 4, 8 Read (8) 0014 Model 3000 s Modbus Address Read / Write (9) 0015 Software release no. Read 0016 DeviceNet baud rate 0, 1, 2 Read / Write (10) Consider that: Sample weight value (MSW) Sample weight value (LSW) 0-Total Capacity Write (9) 0031 Command register 1, 2, 3 Write (11) All data contained in the Modbus words are expressed in hexadecimal format. MSW = Most Significant Word LSW = Least Significant Word All parameters represented with a double word are Long unsigned integers For those parameters represented with a double word, but not greater than FFFF (65535 decimal), the MSW always contains Note: 1. The data contained in this word must be coded into binary in order to get the info given in Table Value represented with a double word. Refer to page 19 for details. 3. Values expressed as number of counts. Refer to page 20 for details. 4. Refer to the Table on page Average of the load cells nominal sensitivities (in mv/v). 5 digits without decimal point (x.xxxx) 6. Sum of the load cells nominal capacities. Value represented with a double word. 7. Refer to the Table on page Highlights possible problems on the load cells. Refer to Table 2 9. Value of the sample weight used to perform the Full Scale calibration. Value represented with a double word = 125 kbps; 1 = 250 kbps; 2 = 500 kbps 11. Refer to Table 3 for the Command Register functions. 22

23 Table 1 - Modbus Word 0000 (Status Register) Description Bit s meaning 0 1 Weight stability NO YES Scale unloaded (*) NO YES Emulated load cell NO YES Under load condition NO YES Overload condition NO YES Off range condition NO YES Example: If the Modbus word 0000 contains the value 03, the conversion into binary gives the following sequence of bits: The digit at the right hand side matches with the 1st bit (Weight stability), therefore the values given in this example are equivalent to: Weight stability = YES Scale unloaded = YES Emulated load cell = NO Under load condition = NO Overload condition = NO Off range condition = NO (*) The scale is considered unloaded (empty) when the weight value is within +/- 20 counts of zero. Table 2 - Modbus Word 0013 (Load cells operating mode) Under normal conditions the hex value contained in the Modbus Word 0013 is 00 In case of errors the hex value will take the following : Content of the Meaning Modbus word Normal condition -no errors- 01 Load Cell 1 failure 02 Load Cell 2 failure 04 Load Cell 3 failure 08 Load Cell 4 failure The Load cell failure can be caused by various things, such as: Load cell cable interrupted One or more wires of the load cell cable are disconnected Load cell signal is outside of the measuring range The load cell failure involves the emulation procedure to be performed. The emulation procedure takes place by writing the function code 3 in the Command Register (Modbus word 0031), see Table 3. Table 3 - Modbus Word 0031 (Command Register) Function code written in the word 0031 Command performed Notes 01 Zero Calibration (1) 02 Full Scale Calibration (2) 03 Faulty load cell emulation (3) 23

24 Notes: Make sure that the weighing system is unloaded prior to performing the Zero Calibration command. The Full Scale calibration command must be performed after a known weight has been applied on the scale and after writing the weight value (in hexadecimal format) in the Modbus words 0029 and If the value is < it must be written in the word 0030 (LSW) only. If the value is > also the word 0029(MSW) must be written. Refer to page 19 for further details about data defined as Long unsigned integer. Through the emulation procedure the faulty load cell is excluded from the weight calculation and normal operations continue with the remaining one, two or three load cells. The transmitter automatically assigns the faulty load cell a theoretical value based on the average of the weight values detected by the remaining load cells still working properly. The emulation procedure compensates for a LC missing output allowing the weighing system to remain in operation until a permanent repair is done. The emulation accuracy depends on the deviation from the ideal load cell distribution. For instance, the better the LC s distribution (ideal: 25% each with 4 LC s or 33.3% each with 3 LC s) the more accurate the emulated result will be. 24

25 The Profibus-DP Protocol Profibus-DP is one of the optional protocols handled by the Model 3000 Fieldbus Transmitter. INPUT DATA AREA Bytes Variable Values or ranges (min. max.) Notes Status Register 0, 1, 2, 4, 8, 10, 20 (1) Total weight value (MSB) Total weight value (LSB) 0 - Total capacity (2) Weight value LC channel LC 1 capacity (3) Weight value LC channel LC 2 capacity (3) Weight value LC channel LC 3 capacity (3) Weight value LC channel LC 4 capacity (3) Digital Filter 0-9 (4) Load Cell s nominal sensitivity (5) Load Cell s Total capacity (MSB) Load Cell s Total capacity (LSB) 0 - Total capacity (6) Number of active LC channels 2, 3, 4 (7) Display division value 0-11 (8) Load cells operating mode 0, 1, 2, 4, 8 (9) Model 3000 s Profibus address (10) DeviceNet baud rate 0, 1, 2 (11) Software release number (12) Consider that: MSB = Most Significant Bytes LSB = Least Significant Bytes For those parameters represented by 4 bytes (Total weight value and LC s Total capacity), but not greater than FF FF (= decimal), the MSB always contain Notes: (1) The data contained in byte 01 must be converted to binary in order to get the info given in the Table 4 (2) Value represented by 4 bytes. Refer to page 19 for details. (3) Values expressed as number of counts. Refer to page 20 for details. (4) Data are contained in byte 15. Refer to the Table on page 13 (5) Average of the load cells nominal sensitivities (in mv/v). 5 digits without decimal point (x.xxxx) (6) Sum of the load cells nominal capacities. Value represented by 4 bytes (7) Data is contained in byte 23. (8) Data is contained in byte 25. Refer to the Table on page 20 (9) Data is contained in byte 27. Highlights possible problems on the load cells. Refer to Table 5 (10) Data is contained in byte 29. (11) Data is contained in byte = 125 Kbs; 1 = 250 Kbs; 2 = 500 Kbs. (12) Data is contained in byte

26 Table 4 - Byte 01 (Status register) Bit Meaning Bit s status Weight stability NO YES 1.1 Scale unloaded (*) NO YES 1.2 Emulated load cell NO YES 1.3 Under load condition NO YES 1.4 Over load condition NO YES 1.5 Off range condition NO YES (*) The scale is considered unloaded (empty) when the weight value is within +/- 20 counts of Zero. Table 5 - Byte 27 (Load cells operating mode) Content of Byte 27 Meaning 00 Regular condition - no errors - 01 Load Cell 1 failure 02 Load Cell 2 failure 04 Load Cell 3 failure 08 Load Cell 4 failure In regular conditions the content of byte 27 is 00. In case of errors the byte 27 takes one of the hex values listed above in Table 5. For details about load cell failure and the emulation procedure refer to page

27 OUTPUT DATA AREA Bytes Variable Values or Ranges (Min. Max.) Command Register (*) Sample Weight Value (MSB) Sample Weight Value (LSB) Notes 0 - Total Capacity (1) Digital Filter 0-9 (2) LC s Nominal Sensitivity (3) LC s Total Capacity (MSB) LC s Total Capacity (LSB) 0 - Total Capacity (4) Number of active LC Channels 2, 3, 4 (5) Display Division Value 0-11 (6) Model 3000 s Profibus Address (7) DeviceNet Baud Rate 0, 1, 2 (8) Boot Loader B (42 Hex) (9) Not Used Not Used Not Used Not Used (*) Command Register Function Code Command to be performed 1 Zero Calibration 2 Full Scale Calibration 3 Load Cell Emulation 4 Digital Filter Value 5 Load Cell s Nominal Sensitivity 6 Load Cell s Total Capacity 7 Number of Active Load Cell Channels 8 Display Division Value 9 Model 3000 s Profibus Address 10 DeviceNet Baud Rate Procedure to perform commands 1 and 3: Write into Byte 01 of the Command Register variable the function code corresponding to the command to be performed. Procedure to perform commands 2, 4, 5, 6, 7, 8, 9, 10: Write the value to be programmed in the corresponding byte of the output data area. Write into Byte 01 of the Command Register variable the function code corresponding to the command to be performed. 27

28 Example: To program the digital filter you have to write its value into Byte 07, then write the function code # 4 into Byte 01 of the Command Register variable. Important: Always write the values before writing the corresponding function codes. Note: (1) Value represented by 4 bytes. Refer to page 19 for details. (2) Data must be written in byte 07. Refer to the Table on page 13 (3) Average of the load cells nominal sensitivities (in mv/v). 5 digits without decimal point (x.xxxx) (4) Sum of the load cells nominal capacities. Value represented by 4 bytes (5) Data must be written in byte 15. (6) Data must be written in byte 17. Refer to the Table on page 20 (7) Data must be written in byte 19. (8) Data must be written in byte = 125 Kbs; 1 = 250 Kbs; 2 = 500 Kbs. (9) Data must be written in byte 23 The GSD File Structure ;============================================================ ; Profibus Device Database of HMS Industrial Networks. ; ; Model : Anybus-IC DP-V0 ; Description : Anybus-IC DP-V0 slave ; Language : English ; Date : 16 March 2007 ; Author : HMS Industrial Networks ; ; Revision Log: ; ; : Updated revision information. Cleared old revision history. ; : Updated revision information. ; : Updated SW revision information. ; : Updated SW revision information. ; : Updated Model Name. ; : Updated SW revision information. ; : Updated SW revision information. ; : Updated SW revision information. ; ;============================================================ # Profibus-DP GSD-Revision = 3 ; Device Identification Vendor Name = "HMS Industrial Networks" Model Name = "Anybus-IC PDP" Revision = "Version 2.10" Ident Number = 0x1810 Protocol Ident = 0 ; DP protocol Station Type = 0 ; Slave device FMS supp = 0 ; FMS not supported Hardware Release = "Version 2.3" Software Release = "Version 2.11" ;Used bitmap Bitmap Device = "ABIC-DE" Bitmap Diag = "ABIC-DI" Bitmap SF = "ABIC-SF" 28

29 The GSD File Structure (cont d) ; Supported Baud Rates 9.6-supp = supp = supp = supp = supp = supp = 1 1.5M-supp = 1 3M-supp = 1 6M-supp = 1 12M-supp = 1 ; Maximum responder time for supported baud rates MaxTsdr-9.6 = 15 MaxTsdr-19.2 = 15 MaxTsdr = 15 MaxTsdr = 15 MaxTsdr = 15 MaxTsdr-500 = 15 MaxTsdr-1.5M = 25 MaxTsdr-3M = 50 MaxTsdr-6M = 100 MaxTsdr-12M = 200 ; Supported hardware features Redundancy = 0 ; not supported Repeater Ctrl Sig = 2 ; TTL 24V Pins = 0 ; not connected Implementation Type = "NP30" ; Supported DP features Freeze Mode supp = 1 ; supported Sync Mode supp = 1 ; supported Auto Baud supp = 1 ; supported Set Slave Add supp = 1 ; supported ; Maximum polling frequency Min Slave Intervall = 1 ; 100 us ; Maximum supported sizes Modular Station = 1 ; modular Max Module = 24 Max Input Len = 144 Max Output Len = 144 Max Data Len = 288 Modul Offset = 1 Fail Safe = 1 ; Data telegram without data in state CLEAR accepted Slave Family = 0 Max Diag Data Len = 6 29

30 The GSD File Structure (cont d) ; Definition of modules Module = "INPUT: 32 Byte (16 word)" 0x5F ; EndModule ; Module = "OUTPUT: 16 Byte ( 8 word)" 0x67 ; EndModule ; Module = "OUTPUT: 8 Byte ( 4 word)" 0x63 ; EndModule NOTE: The Master (PC, PLC or DCS) must be configured to handle 32 Input bytes and 24 Output bytes. Notes about the Profibus connection The cable to be used in a Profibus network is a twisted pair shielded cable. The cable impedance should be within 100 and 130 Ohms (f > 100 khz). The cable capacitance (measured between wire and wire) should be less than 60 pf/meter. The minimum section of each single wire shouldn t be less than 0.22 mm 2 Depending on the performances requested, both Type A and Type B cables can be used in a Profibus network. The following table provides the specifications of the cable to be used: FEATURE TYPE A CABLE TYPE B CABLE Impedance 135 to 165 ohms (f = 3-20 MHz) 100 to 300 ohms (f > 100 khz) Capacitance < 30 pf/m < pf/m Resistance < 110 ohms/km - Single wire section > 0.34 mm > 0.22 mm² The following table gives the maximum cable lengths (Type A or B) and the different communication baud rates. Baud Rate (kbit/s) Type A cable length (meters) Type B cable length (meters)

31 Details about the Profibus module used on the Model 3000 Fieldbus Transmitter (AnyBus-IC PDP) AnyBus-IC PDP is a module developed for the communication inside a Profibus-DP network and operates as a Profibus-DP slave module. Main features: Max. 128 bytes input / 128 bytes output At power-on the Model 3000 s microprocessor initializes the Anybus-IC module to exchange 32 Input bytes and 24 Output bytes over the Profibus network 32 input bytes and 22 output bytes contain significant data. Supports all Profibus baud rates from 9,6 kbit/s to 12 Mbit/s The AnyBus-IC PDP supports automatic baud rate detection, which means that the actual baud rate only has to be configured in the Profibus master. Galvanically isolated bus electronics The bus power is separated from other electronics via a DC/DC converter. The send and receive signals are isolated via opto-couplers. The ID Profibus number of the AnyBus-IC module (included in the GSD file) is 1810h Profibus-DP Connector (Sub-D 9-pin) Pin Description Function Housing Shield - 1 Not connected - 2 Not connected - 3 B-Line, Positive RS-485 Rxd/Txd Non-inverting Rxd/Txd 4 RTS, Request To Send Request to send 5 GND BUS GND from RS BUS + 5 V from RS Not connected - 8 A-Line, Negative RS-485 Rxd/Txd Inverting Rxd/Txd 9 Not connected - 31

32 The DeviceNet Protocol DeviceNet is one of the optional protocols handled by the Model 3000 Fieldbus Transmitter. INPUT DATA AREA Bytes Variable Values or ranges (min. max.) Notes Status Register 0, 1, 2, 4, 8, 10, 20 (1) Total weight value (MSB) Total weight value (LSB) 0 - Total capacity (2) Weight value LC channel LC 1 capacity (3) Weight value LC channel LC 2 capacity (3) Weight value LC channel LC 3 capacity (3) Weight value LC channel LC 4 capacity (3) Digital Filter 0-9 (4) LC s nominal sensitivity (5) LC s Total capacity (MSB) LC s Total capacity (LSB) 0 - Total capacity (6) Number of active LC channels 2, 3, 4 (7) Display division value 0-11 (8) Load cells operating mode 0, 1, 2, 4, 8 (9) Model 3000 s DeviceNet address (10) DeviceNet baud rate 0, 1, 2 (11) Software release number (12) Consider that: MSB = Most Significant Bytes LSB = Least Significant Bytes For those parameters represented by 4 bytes (Total weight value and LC s Total capacity), but not greater than FF FF (= decimal), the MSB always contain Notes: (1) The data contained in byte 01 must be coded into binary in order to get the info given in Table 4 (2) Value represented by 4 bytes. Refer to page 19 for details. (3) Values expressed as number of counts. Refer to page 20 for details. (4) Data is contained in byte 15. Refer to the Table on page 13 (5) Average of the load cells nominal sensitivities (in mv/v). 5 digits without decimal point (x.xxxx) (6) Sum of the load cells nominal capacities. Value represented by 4 bytes (7) Data is contained in byte 23. (8) Data is contained in byte 25. Refer to the Table on page 20 (9) Data is contained in byte 27. Highlights possible problems on the load cells. Refer to Table 5 (10) Data is contained in byte 29. (11) Data is contained in byte = 125 Kbs; 1 = 250 Kbs; 2 = 500 Kbs. (12) Data is contained in byte

33 Table 4 - Byte 01 (Status register) Bit Meaning Bit s status Weight stability NO YES 1.1 Scale unloaded (*) NO YES 1.2 Emulated load cell NO YES 1.3 Under load condition NO YES 1.4 Over load condition NO YES 1.5 Off range condition NO YES (*) The scale is considered unloaded (empty) when the weight value is within +/- 20 counts of Zero. Table 5 - Byte 27 (Load cells operating mode) Under normal conditions the contents of byte 27 is 00. In case of errors byte 27 takes one of the hex values listed in Table 5. Content of Byte 27 Meaning 00 Normal condition - no errors - 01 Load Cell 1 failure 02 Load Cell 2 failure 04 Load Cell 3 failure 08 Load Cell 4 failure Notes: Load cell failures can depend on various things, such as: Load cell cable interrupted One or more wires of the load cell cable are disconnected Load cell signal outside of the measuring range A load cell failure requires the emulation procedure to be performed. The emulation procedure takes place by writing the function code 3 in the Command Register. See page 20 for additional information. Through the emulation procedure the faulty load cell is excluded from the weight calculation and normal operations continue with the remaining one, two or three load cells. The transmitter automatically assigns the faulty load cell a theoretical value based on the average of the weight values detected by the remaining load cells still working properly. The emulation procedure compensates for a LC missing output allowing the weighing system to remain in operation until a permanent repair is done. The emulation accuracy depends on the deviation from the ideal load cell distribution. For instance, the better the LC s distribution (ideal: 25% each with 4 LC s or 33.3% each with 3 LC s) the more accurate the emulated result will be. 33

34 OUTPUT DATA AREA Bytes Variable Values or ranges Notes (min. max.) Command Register Sample Weight Value (MSB) 0 Total capacity (1) Sample Weight Value (LSB) Digital Filter Value 0 9 (2) Load Cell s Nominal Sensitivity (3) Load Cell s Total Capacity (MSB) 0 Total capacity (4) Load Cell s Total Capacity (LSB) Number of Active Load Cell Channels 2, 3, 4 (5) Display Division Value 0 11 (6) Model 3000 s DeviceNet Address (7) DeviceNet Baud Rate 0, 1, 2 (8) Boot Loader B (42 hex) (9) Not Used Not Used Not Used Not Used Command Register Function code Command to be performed 1 Zero Calibration 2 Full Scale Calibration 3 Load Cell Emulation 4 Digital Filter Value 5 Load Cell s Nominal Sensitivity 6 Load Cell s Total Capacity 7 Number of Active Load Cell Channels 8 Display Division Value 9 Model 3000 s DeviceNet Address 10 DeviceNet Baud Rate Procedure to perform commands 1 and 3: Write into byte 01 of the Command Register variable the function code corresponding to the command to be performed. Procedure to perform commands 2, 4, 5, 6, 7, 8, 9, 10: Write the value to be programmed into the corresponding byte of the output data area. Write into byte 01 of the Command Register variable the function code corresponding to the command to be performed. Example: To program the digital filter you have to write its value into byte 07, then write the function code # 4 into byte 01 of the Command Register variable. Important: Always write the values before writing the corresponding function codes. Notes: (1) Value represented by 4 bytes. Refer to page 19 for details. (2) Data must be written into byte 07. Refer to the Table on page 13 (3) Average of the load cells nominal sensitivities (in mv/v). 5 digits without decimal point (x.xxxx) (4) Sum of the load cells nominal capacities. Value represented by 4 bytes (5) Data must be written into byte 15. (6) Data must be written into byte 17. Refer to the Table on page 20 (7) Data must be written into byte 19. (8) Data must be written into byte = 125 Kbs; 1 = 250 Kbs; 2 = 500 Kbs. (9) Data must be written into byte 23 34

35 The EDS File Structure [File] DescText = "Anybus-IC - DeviceNet slave/adapter module"; CreateDate = ; CreateTime = 07:23:00; ModDate = ; ModTime = 14:30:37; Revision = 3.2; [Device] VendCode = 90; VendName = "HMS Networks"; ProdType = 12; ProdTypeStr = "Communications Adapter"; ProdCode = 61; MajRev = 3; MinRev = 4; ProdName = "Anybus-IC DeviceNet"; DNetQC = 0x0001, $ Quick Connect supported at Powerup 265; $ 265 ms Powerup time [IO Info] Default = 0x0001; $ Default IO Connection = Poll PollInfo = 0x000F, $ Compatible IO type mask = All connections 1, $ Input1 1; $ Output1 StrobeInfo = 0x000F, $ Compatible IO type mask = All connections 1, $ Input1 1; $ Output1 COSInfo = 0x0007, $ Compatible IO type mask = All connections 1, $ Input1 1; $ Output1 CyclicInfo = 0x000B, $ Compatible IO type mask = All connections 1, $ Input1 1; $ Output1 Input1 = 1, $ 1 byte 0, $ All bits are significant 0x000F, $ Compatible IO type mask = All connections "ABIC Produce", $ Name 6, $ Path size " ", $ Assembly object, Inst 100, Attr 3 Data produced by the Anybus-IC"; Output1 = 1, $ 1 byte 0, $ All bits are significant 0x000F, $ Compatible IO type mask = All connections 35

36 "ABIC Consume", $ Name 6, $ Path size " ", $ Assembly object, Inst 150, Attr 3 "Data consumed by the Anybus-IC "; [ParamClass] MaxInst = 0; $ Max Instances - total # configuration parameters Descriptor = 0x0000; $ Parameter Class Descriptor - No parameters CfgAssembly = 0; $ The config assembly is not supported NOTE: The Master PC/PLC/DCS must be configured to handle 34 Input bytes and 24 Output bytes. Details about the DeviceNet module used on the Model 3000 Fieldbus Transmitter (AnyBus-IC DEV) The AnyBus-IC DeviceNet integrates all analog and digital functionality required to communicate on a DeviceNet network into a single chip. Features Identity Object Customization This makes it possible for a configuration tool to identify the module as a special implementation and not as a general AnyBus-IC module. I/O data The module supports up to 128 input bytes and 128 output bytes. At power-on the transmitters microprocessor initializes the Anybus-IC module to exchange 34 Input bytes and 24 Output bytes over the DeviceNet network Supported data types: Polled I/O data COS/Cyclic I/O data Bitstrobe I/O data Application Parameters Application specific parameters can be created by the application during startup. Acyclic Data and Parameter Data Mapping Application Parameters can be accessed from the fieldbus by mapping them to a Vendor Specific DeviceNet Object. EDS-File Each device in a DeviceNet network is associated with an EDS-file, containing all necessary information about the device. This file is used by the network configuration utility during network configuration. The EDS-file is supplied on a CD which is included with the device DeviceNet connector (removable terminal block, 5-positions) Pin Description Function 1 V- - 2 CAN_L - 3 Shield Non-inverting RxD/TxD 4 CAN_H Request to send 5 V+ GND from RS