-wire Bridge Connection Excitation for to 30 Ω Load Cells 00 Volt (3-way) Isolation Excellent Accuracy (0.0%) DIP Switch Configuration Digital Input Tare Calibration RS8 Modbus RTU Superior Flexible Power: 0-0 VDC or 9-28 VAC (0-0 Hz) DIN Rail Mount (3 mm) Removable Terminal Blocks The ZNET model Z-SG provides configuration for the most popular load cells and measurement spans commonly used: mv to 28 mv with a V excitation. This translates to load cell sensitivity of 0.2 mv/v to 2. mv/v. The Z-SG has a configurable DC current or voltage output. The Z-SG also has a Digital I/O port that may be used as either a digital input (Tare) or output. The Z-SG completes its unprecedented flexibility by including a standard serial communication protocol, Modbus RTU, via RS8 bus or direct via RS232. The Z-SG may be a Modbus slave. PC Configuration software is available for enhanced operation and Modbus register configuration. LEDs on the front indicate status and power and provide feedback for the Modbus communications. Signal Conditioning flexibility and use made easy from ioselect. General Specification Input Digital Excitation Output Current Voltage Digital Power Power Consumption 2 W RS8 Interface -wire Bridge span mv to 28 mv Sensitivity of 0.2 mv/v to 2. mv/v 30 V Maximum Tare or Span Calibration Vdc @ ~0 ma (87. Ω min) = Up to Four 30 Ω Bridges in Parallel -20 ma, 0-20 ma @ 2 V (00 Ω max) 0- V, 0-0 V @ ma (2 kω min) 30 V @ 0 ma Maximum (external) 0 to 0 Vdc or 9 to 28 Vac 2-wires 200 to,200 baud ModBus RTU Slave Protocol Performance Specifications Isolation 00 Vac Accuracy 0.0% Calibration 0.0% Linearity 0.002% Thermal Coefficient Sampling Frequency 2.3 to.7 Hz = Response Time. ms to 80 ms Operating Temp -0 to C (-0 to 0 F) Humidity 30 to 90% @ 0 C (non-condensing) Weight Dimensions 0 g (.9 oz) 7. x 00 x 2 mm 0.9 x 3.9 x. in Mounting 3 mm DIN 277 Ordering Information: IOS-Z-SG Accessories: IOS-UP-NET Configuration Software Fax: (800)303-38 Ph: (877) 3GET IOS (33-87) rev: 0/07
Installation Instructions Install on horizontally mounted TS 3 DIN rail. For optimum operation and product life make sure adequate ventilation is provided. Severe operating conditions are defined as follows: Power supply voltage > 30 Vdc or 2 Vac Input sensor powered from Z-SG Output current sourced from Z-SG Modules may need to be separated by at least mm if: The panel temperature exceeds C and one or more of the above conditions exist. The panel temperature exceeds 3 C and 2 or more of the above conditions exist. Wiring Diagrams Power Supply Digital Input Digital Output Load 2 9-28 Vac 3 or 9-0 Vdc V 2 Vdc V 2 Vdc The upper limits must not be exceeded! Serious damage could result 7 8 Excitation Sense - Sense - Excitation Bridge Input Signal - Signal 9 2 0 -Wire Input and Output Configuration The Z-SG may be configured using a calibrator, the live load cell system (if control of the full scale is available), via a PC or via Modbus RTU protocol. There are 3 DIP-switches on the Z-SG: SW, SW2 and SW3. SW defines the baud rate and Modbus address for Modbus communications. SW3 should be ON if the Z-SG is the last device on the serial communications bus. SW2 defines the use of the Digital I/O, sets the input range (aka: sensitivity), sets the output range and the function of the push button. The push button can be locked out so no inadvertent press will affect the settings. It may be used to define the tare (constant load) and full scale input (see the next page for details). The configurable digital I/O port is useful as an output to indicate a stable weight has been reached. When configured as an input the digital I/O port is useful to set the zero for the tare function. Enhanced functions are available using Modbus RTU or the configuration software (See the Modbus Register definitions). The Excitation is fixed at Vdc. 7 8 Excitation Sense - Sense - Excitation Output Voltage V -Wire Signal - Signal 9 2 0 Baud Rate & Modbus Address Selection SW SW SW3 Bus Terminator 2 OFF ON Baud 900 9200 3800 700 Address EEPROM 2 3 3 Output Current Terminal Connections. Digital Input/Output 2. Power 3. Power. Output. - Output. Digital Input/Output 7. Excitation 8. Sense 9 Signal 0. - Excitation. - Sense 2. - Signal Digital I/O, Output Range & Input Sensitivity SW2 Digital I/O Input Output SW2 Output Range 0-0 V 0 - V 0-20 ma - 20 ma SW2 Sensitivity ± mv/v ± 2 mv/v ± mv/v ± 8 mv/v ± mv/v ± 32 mv/v ± mv/v ± 28 mv/v RS8 Connections Legend = ON = N.A. 2 3 ERR PWR RX TX COM 7 8 9 0 2 Push Button Function SW2 Calibration Default Tare Full Scale Stored Full Scale is the Excitation multiplied by the Sensitivity, e.g.: (Excitation = V) 2 mv/v x V = 0 mv (877) 3GET IOS (33-87)
Manual Calibration ) Set the DIP switches for the desired sensitivity and output ranges. Set SW2- = OFF and SW2- = ON. 2) Power the Z-SG, connect a multi-meter to the output and a millivolt calibrator to the Signal and -Signal terminals. 3) Using a calibrator set the input to the TARE (0% input) level. ) Press and hold the push-button until the yellow LED is flashing. The TARE value is stored. NOTE: Release the button within seconds from the moment the LED begins to flash or the calibration process will end. ) Using the calibrator introduce the TARE FULL SCALE (00% input) level to the input. ) Set SW2- = ON (SW2- remains ON). 7) Press and hold the push button until the yellow LED is flashing (See NOTE above). 8) Press and hold the push button until the yellow LED stops flashing. The TARE FULL SCALE level is stored. 9) Confirm that input and output correspond as desired by setting the calibrator to TARE for 0% output. 0) Set input to TARE FULL SCALE to confirm output is 00%. Software Calibration During the entire procedure read the register ADC_LONG (0032-0033) with a 200-00 ms interval to maintain communication from the front jack. TARE Acquisition ) Set the DIP switches for the desired sensitivity and output ranges. Set SW2- & = ON. 2) Connect the Z-SG to the PC and power. 3) Enter the password 0xFACB in the RESET register (0039). ) Introduce the TARE level to the Signal and -Signal terminals. Wait seconds for stabilization. ) Acquire 0 samples from the register ADC_LONG (0032-0033) at intervals of 00 ms then calculate the mean value. ) Save the mean value obtained in the long TARE register TARE_LONG (000-0007). 7) Provide the command for a Reset by entering the 0xABAC value in the register RESET (0039). FULL SCALE Acquisition ) Follow steps - above with the exception of using the FULL SCALE level in place of the TARE level. 2) Save the mean value in the long FULLSCALE variable. 3) Define the following long support value: NET=FULLSCALE - TARE. ) Save the net FULL SCALE value in the float variable: TECHN ) Define the following support float variable: K_WEIGHT_FLOAT=TECHN/NET. ) Save the long support variable value NET in the register: LONG (000-00 ). 7) Save the support float variable value K_WEIGHT_FLOAT in the register: K_WEIGHT_FLOAT(00-00). 8) Save the support float variable value TECHN in the register: FL(0008-0009). 9) Provide the command for a Reset by entering the 0xABAC value in the register RESET(0039). Description of Operation The input's measured value is translated into an analog output signal (current or voltage). The input is available through Modbus RTU protocol upon query by RS8 bus and/or RS232 jack. Serial communication parameters can be made either by Modbus RTU or DIP switch. The Z-SG's various functions are described below. Retransmitted Output The analog output permits the retransmission of the net weight as follows: -At intermediate values, the progression is linear from 0 to 00%. -If the Net Weight in units of weight < 0, the output = 0% - If the Net Weight in units of weight > than the net full scale, the output = 00%. Digital Input/Output The Z-SG offers the ability to select either a digital input or a digital output. The selection is made only by DIP-switch. Digital Input The digital input permits the zeroing of the tare. Digital Output The output can be configured via Modbus for three different operating modes and switches to ON or OFF status (according to Modbus setting) whenever: ) The Net Weight exceeds the Net Full Scale. 2) The Weight is stable and the Net Weight exceeds the threshold. 3) The Weight is stable. 877 3 GET IOS (877.33.87) RS-232 Configuration Cable DB9 9 GND 3. mm Mini-Plug Tx Rx GND Tx Rx Dimension Diagram
Description of Operation (continued) Stable Weight Function Informs the user of the precise moment the weight has stabilized. This information is available via Modbus register (see Register 0037: STATUS) and can also be signalled by digital output (after previous selection and programming by Modbus). This function is characterized by the two parameters: Weight and Time. The weight is considered stable whenever the net weight in Time has changed by a quantity lower than Weight. Remote Zero Setting of the Tare The Z-SG permits the zeroing of the tare value by means of digital input (whenever enabled) or via Modbus register (see Register 0037: STATUS). Rejection at 0 and 0 Hz Rejection to interference at both 0 and 0 Hz can be enabled at the same time. See Appendix A for details on setting and optimization Calculation of Measurement Mean Value The mean value of a settable number of samples (NR_SAMPLINGS: to 27) can be calculated. In this way, the NetWeight displayed is the mean value calculated, and the period for which a new value is available is equal to NR_SAMPLINGS* Sampling period. Modbus Registers The Z-SG has MODBUS bits (words) registers, accessible by RS8 or RS232 serial communication. This means data can be acquired from a PC or a controller. The next paragraphs describe the supported MODBUS commands, and the functions of the registers. SUPPORTED MODBUS COMMANDS Code Function Description 03 * Read Holding Registers Read up to word registers 0 * Read Input Registers Read up to word registers 0 Write Singe Register Write a word register Write Multiple Registers Write up to word registers * The two functions have the same effect HOLDING REGISTERS The -bit Holding Registers have the following structure: Most Significant bit Bit Index Least Significant bit FLASH REGISTERS MACHINE ID 000 R Bit [:8]: contain the module s ID: 23 (hexadecimal: 0x7) Bit [7:0]: contain the firmware s revision. FW_CODE Firmware s Internal Code. 0002 R HW_REL Instrument s Hardware Version 0003 R ADDR Set the Module s Address and Parity Control 000 R/W Bit [:8] Set the Module s Address. Permissible values from 0x00 to 0xFF (0-2). Default = BAUDR Bit [7:0] Bit [:8] Bit [7:0] TARE_LONG_H TARE_LONG_L FL_H FL_L LONG_H LONG_L K_WEIGHT_ Set the Parity Control: 0x00 = No Parity (Default) 0x0 = Even Parity 0x02 = Odd Parity Set the Baud Rate and the Response Delay Time Set the Baudrate: 0x00: 800 Baud 0x0: 900 Baud 0x02: 9200 Baud 0x03: 3800 Baud (Default) 0x0: 700 Baud 0x0: 200 Baud 0x0: Not permitted 0x07: 200 Baud Set the response delay time in characters that represents the number of pauses of characters to be entered between the end of the Rx and the start of the Tx message. Default = 0 tare value (long format, MSW) tare value (long format, LSW) Net measurement full scale in technical units (floating point format, MSW) Net measurement full scale in technical units (floating point format, LSW) Set the net measurement full scale in technical units (kg, lbs, etc.) and serves to display the new weight in technical units (FLOAT WEIGHING) Default = 0000.00. net full scale value (long format, MSW) net full scale value (long format, LSW) Bit to unit of weight conversion value (float format, MSW) 000 R/W 000 R* 0007 R* 0008 R* 0009 R* 000 R* 00 R* 00 R* 3 2 0 9 8 7 3 2 0 Word ( Bits): MODBUS Register The Bit notation [x:y] shown in the table indicates all the bits from x to y. For example, Bit [2:] indicates bit 2 and bit, and illustrates the meaning of the various linked combinations of the values of the two bits. Remember that the MODBUS 3,, and single and multiple reading and writing functions can be executed on the following registers. The following indication (only readable or also writable) is provided for every register: R: Readable W: Writable R*: Always readable. Writable only in any of the three following cases: SW2-=OFF and SW2-=ON, SW2-=ON and SW2-=OFF, or whenever the correct password has been entered (during the set up phase). MSW = Most Significant Word; LSW = Least Significant Word K_WEIGHT_ THRES_ THRES_ WEIGHT_ Bit to unit of weight conversion value (float format, LSW) Threshold in unit of weight (floating point format, MSW) If the new weight (WEIGHT_FLOAT: 003-3) exceeds the threshold value set and the weight is stable, the digital output (when set in operating mode) is closed or opened Threshold in unit of weight (floating point format, LSW) Weight variation in technical units accepted for stable weight (float format, MSW) Together with Register 0020 ( TIME), permits the establishment of when the weight is stable. This represents the weight variation in units of weight accepted for stable weight. The weight is considered stable whenever the net weight in the Time has changed by a quantity lower than Weight. Default = 00 R* 00 R/W 007 R/W 008 R/W 877 3 GET IOS (877.33.87)
FLASH REGISTERS WEIGHT_ TIME RAM REGISTERS ADC_LONG_H Raw A/D value at 2 bits (MSW) 0032 R ADC_LONG_L Raw A/D value at 2 bits (LSW) 0033 R WEIGHT_SHORT Contains the new weight value in ±0000 scale Net weight value in ±0000 scale which the mean value must be calculated. The WEIGHT_FLOAT is equal to the tare. Equal to 0000 when the WEIGHT_FLOAT is equal to the FL (Net Full Scale). Limited: -000 to 000. WEIGHT_ WEIGHT_ DIGITAL_OUT_ TYPE CONFIG Bit [:8] Bit [7] Bit [:0] NR_SAMPLINGS 877 3 GET IOS (877.33.87) Net weight value in unit of weight (floating point format, MSW) Net weight value in unit of weight (floating point format, LSW) 003 R 003 R 003 R STATUS Status register 0037 R/W Bit [:] Not used Bit [] Stable weight : Weight is stable Bit [3] Tare zero-setting request : The zero-setting of the tare is required. Bit [2] Weight 0 : Net Weight = 0 Bit [] Bit [0] Weight variation in technical units accepted for stable weight (float format, LSW) Time in units of 00 ms used to establish whether the weight is stable. This is the parameter that together with Weight establishes Stable Weight. It is expressed in units of 00 ms. Stable Weight occurs when the net weight in Time has change by a quantity lower than Weight. Default = (00 ms) Sets the shifting of the digital output - if enabled by DIP switch Not used Defines the change of the output upon the appearance of the condition set by the Bit [:0]: 0: The output is normally opened and closes upon the condition. : The output is normally closed and opens upon the condition. Defines the operation of the digital output. Changes state with any of the following: 0: The Net Weight exceeds the Net Full Scale (Default). : The Weight is stable and the Net Weight exceeds the threshold. 2: The Weight is stable Configuration register to set the rejection and sampling frequency Sets the sampling frequency and interference rejection (See Appendix A). Default = 20 (0x00D2) Set the number of A/D samplings which the mean value will be calculated The number of samples which the mean value must be calculated. The WEIGHT_FLOAT register provides the mean value calculated. Permissible value: -27. Default = 0. Net Weight Net Full Scale : Net Weight Net Full Scale Not used 009 R/W 0020 R/W 002 R/W 0022 R/W 0023 R/W RAM REGISTERS Value of Register: CONFIG (0022) STATUS_DIP- DIP-switch status display 0038 R SWITCH Bit [] Bit [] Bit [3] Bit [2] Bit [] Bit [0] Bit [9] Bit [8] Bit [7] Bit [] Bit [] Bit [] Bit [3] Bit [2] Bit [] Bit [0] Status of SW- Status of SW-2. Status of SW-3. Status of SW-. Status of SW-. Status of SW-. Status of SW-7. Status of SW-8. Status of SW2-. Status of SW2-2. Status of SW2-3. Status of SW2-. Status of SW2-. Status of SW2-. Status of SW2-7. Status of SW2-8. RESET Module reset control register 0039 R/W The command for reset is given by entering the code: 398 (0xABAC) APPENDIX A Configuration of Sampling Frequency, Measurement update Time and Rejection The table below provides the values that can be set in the Modbus register CONFIG (0022) together with the corresponding sampling frequency values and the net weight value update period. The latter depends on the number of samples for which the mean value will be calculated that has been set in the Register NR_SAMPLINGS (0023). In the table below, N indicates the number of samples value NR_SAMPLINGS while also indicating whether rejection is enabled at 0 or 0 Hz. Sampling Frequency (Hz) Measurement Update Time (S) Rejection: 0 Hz Rejection: 0 Hz 27.7 N * 0.00 NO NO 7. N * 0.03 NO NO 82 9.9 N * 0.0200 YES YES 09 37.9 N * 0.02 NO YES 0.7 N * 0.098 NO NO 83 2.82 N * 0.000 YES NO 20. N * 0.000 YES YES 237 2.3 N * 0.078 NO YES EN000--/2002 EN000--2/200 EN00-/200 EN072 Pending ioselect, Incorporated P: 88-37-200, F: 800-303-38, info@ioselect.com rev: 7/08