SENECA Z-SG Advanced Digital Strain Gauge Converter User Manual

SENECA Z-SG Advanced Digital Strain Gauge Converter

SENECA s.r.l.
Via Austria, 26 – 35127 –PADOVA – ITALY
Tel. +39.049.8705355 – 8705359 Fax. +39.049.8706287
Web site: www.seneca.it
Technical assistance: supporto@seneca.it (IT), support@seneca.it (Other) Commercial reference: commerciale@seneca.it (IT), sales@seneca.it (Other)

introduction

This document is property of SENECA srl. Duplication and reproduction are forbidden, if not authorized. Contents of the present document refers to products and technologies described in it. All technical data contained in the document may be modified without prior notice Content of this documentation is subject to periodical revision.
To use the product safely and effectively, read carefully the following instructions before use. The product must be used only for the use for which it was designed and built. Any other use must be considered with full responsibility of the user. The installation, implementation and set-up is allowed only for authorized operators; these ones must be people physically and intellectually suitable. Se t up must be performed only after a correct installation and the user must perform every operation described in the installation manual carefully. Seneca is not considered liable of failure, breakdown, or accident caused for ignorance or failure to apply the indicated requirements. Seneca is not considered liable of any unauthorized changes. Seneca reserves the right to modify the device, for any commercial or construction requirements, without the obligation to promptly update the reference manuals.
No liability for the contents of these documents can be accepted. Use the concepts, examples and other content at your own risk. There may be errors and inaccuracies in this document, that may of course be damaging to your system. Proceed with caution, and although this is highly unlikely, the author(s) do not take any responsibility for that. Technical features subject to change without notice.

Seneca Z-SG / Z-SG-L
CAUTION!
UNDER ANY CIRCUMSTANCES, SENECA S.R.L. OR ITS SUPPLIERS SHALL NOT BE RESPONSIBLE FOR LOSS OF RECORDING DATA/INCOMES OR FOR CONSEQUENTIAL OR INCIDENTAL DAMAGE DUE TO NEGLECT OR RECKLESS MISHANDLING OF Z-SG / Z-SG-L, EVEN THOUGH SENECA IS WELL AWARE OF THESE POSSIBLE

DAMAGES.
SENECA, ITS SUBSIDIARIES, AFFILIATES, COMPANIES OF THE GROUP, ITS SUPPLIERS AND RETAILERS SHALL NOT GUARANTEE THAT THE FUNCTIONS WILL SATISFY COMPLETELY CUSTOMER’S EXPECTATIONS OR THAT Z-SG / Z-SG-L, THE FIRMWARE AND THE SOFTWARE SHALL HAVE NO ERRORS OR WORK CONTINUOUSLY.

Glossary

Modbus RTU

An open protocol for the serial communications developed by Modicon Inc. (AEG Schneider Automation International S.A.S.). Simple and robust, it has since become a de facto standard communication protocol.
For more info http://www.modbus.org/specs.php

General characteristics

• ADC with 24bit resolution
• 4 wires or 6 wires load cell measure mode
• Compression and Traction or only compression load mode
• NR 1 analog output configurable in Current or Voltage mode (only Z-SG model)
• Load cell sensitivity configurable from +-1mV/V to +-64mV/V or virtually every sensitivity
• Measure resolution configurable
• RS232 and RS485 port with Modbus RTU protocol
• Configurable Moving average filtering
• Digital input for Tare acquisition (only Z-SG model)
• General purpose Digital input or Digital output (only Z-SG-L model)
• Digital output with one configurable weight threshold or “stable measure” condition
• Modbus Station address and baud-rate configurable by Dip-Switches

Features

The power supply transformer necessary to supply the module must be comply with EN60742 (Isolated transformers and safety transformers requirements).
To protect the power supply, is recommended to install a fuse.

LEDs for signaling

In the front-side panel there are 4 LEDs and their state refers to important operating conditions of the module.

Load Cell: 4 or 6 Wires Connection

To connect the Z-SG / Z-SG-L to load cell in 4-wires mode:

• short-circuit screw terminal 7 to screw terminal 8;
• short-circuit screw terminal 10 to screw terminal 11.
  Use shielded cables for connections.

ANALOG OUTPUT (ONLY Z-SG MODEL)

The Analog output can be configured in Voltage or Current mode:

”V” means voltmeter, “A” means amperemeter.

• The Analog output is proportional to the net weight measure.
• The Analog Output 0% and 100% can be fully configurable.

“STABLE WEIGHT” CONDITION

Z- SG / Z-SG-L module allows to detect when a weight measure is stable:

• weight stability information is available through 40066 Modbus register (bit Nr 4) or through digital output.
• In particular, a weight measure is stable:
• If the net weight measure variation (reg.40064-40065), in a given time interval (“delta time”, reg.40058), is less than weight interval (“delta weight”, reg.40056-40057).

DIGITAL INPUT / DIGITAL OUTPUT

”V” means equivalent voltage generator.

Z-SG / Z-SG-L module can be configured in digital input mode or (in the alternative) in digital output mode only by Dip-Switch.
In the Z-SG model the digital input can be used for:

• Acquire a tare value
• Alternative for the calibration button
• in the Z-SG-L model, the digital input can be used for acquiring a general purpose input.
• Digital output allows to open/close an optoisolated contac
• In the Z-SG/Z-SG-L model the digital output can be controlled by the firmware with these configurations:
  • gross weight is greater than the load cell end scale
  • weight is stable and net weight is greater than the Threshold
  • weight is stablet

In the Z-SG-L model the digital output can also be controlled from modbus register.

Dip-switches table

In the following tables:

• box without circle means Dip-Switch=0 (OFF state);
• box with circle means Dip-Switch=1 (ON state).

Measure Calibration with Modbus Registers

CALIBRATION WITH EASY SETUP

Use the software “Easy Setup” (download from www.seneca.it) for Configure and Calibrate the Z-SG/Z-SG-L.

CALIBRATION WITH A STANDARD WEIGHT

WARNING
Gross weight (tare + Standard weight) must not to exceed load cell end scale, to avoid serious damage to the cell.

1. Power off the module.

2. Switch Dip-Switch SW2-1 as desired: “OFF”=digital input enabled, digital output disabled; “ON”=digital input disabled, digital output enabled

3. Switch Dip-Switches SW2-2 and SW2-3 as desired: see Dip-Switches table

4. Switch Dip-Switches SW2-4 to “OFF” and SW2-5 to “ON”

5. Switch Dip-Switches SW2-6 to “ON”, SW2-7 to “ON”, SW2-8 to “ON”

6. Power ON the module

7. Write sensitivity value in reg. 40044-40045

8. Write the Standard Weight value in reg. 40048-40049

9. Reset the module (write 0xABAC=43948 in reg.40068)
   New sensitivity and Standard weight are saved in Z-SG/Z-SG-L module.

10. Put the tare on the balance

11. Save the tare value in EEPROM memory (write 0xC2FA=49914 in reg.40068)

12. Put the known weight on the tare

13. Save the known weight in EEPROM memory (write 0xC60C=50700 in reg.40068)

14. witch Dip-switch SW2-1 OFF SW2-2 ON SW2-3 ON SW2-4 OFF SW2-5 ON SW2-6 ON SW2-7 ON SW2-8 ON

CALIBRATION WITHOUT A STANDARD WEIGHT

1. Power off the module before configuring it by Dip-Switches to avoid serious damage due to electrostatic discharges.
2. Switch Dip-Switch SW2-1 as desired: “OFF”=digital input enabled, digital output disabled; “ON”=digital input disabled, digital output enabled
3. Switch Dip-Switches SW2-2 and SW2-3 as desired: see Dip-Switches table
4. Switch Dip-Switches SW2-4 to “OFF” and SW2-5 to “OFF”
5. Switch Dip-Switches SW2-6 to “ON”, SW2-7 to “ON”, SW2-8 to “ON”
6. Power on the module
7. Write sensitivity value in reg. 40044, 40045 (FP)
8. Write load cell end scale in reg. 40046, 40047 (FP)
9. New sensitivity and load cell end scale are saved in Z-SG / Z-SG-L module.
10. Put the tare on the balance
11. Save the tare value in EEPROM memory (write 0xC2FA=49914 in reg.40068)

MEASURE CALIBRATION WITHOUT MODBUS REGISTERS

CALIBRATION WITH A STANDARD WEIGHT USING THE CALIBRATION BUTTON

WARNING
Gross weight (tare + known weight) must not to exceed load cell end scale, to avoid serious damage to the cell.

1. Power off the module before configuring it by Dip-Switches to avoid serious damage due to electrostatic discharges.

2. Switch the Dip-Switches SW2-4 to “ON” and SW2-5 to “ON”. In this way, setting by calibration button is possible.

3. Switch the Dip-Switch SW2-1 to “OFF”. In this way, calibration with known weight using calibration button (or digital input) is possible.

4. Switch the Dip-Switches SW2-2 and SW2-3 as shown in Dip-Switches table, to select one of the possible modalities of analog output.

5. Switch the Dip-Switches SW2-6, SW2-7, SW2-8 to choose the load cell sensitivity (see Dip-Switch table)

6. Power on the module

7. Keep pushed the calibration button (or in alternative, only for Z-SG model, use digital input) until LED ERR is “ON”

8. Release the calibration button

9. Control that the LED ERR is flashing

10. Put the tare on the load cell

11. Keep pushed the calibration button (or in alternative use digital input signal for Z-SG model) until LED ERR switches from flashing to “OFF”
    The module has acquired the tare value.

12. Keep pushed the calibration button (or in alternative use digital input signal) until LED ERR is “ON”

13. Release the calibration button

14. Control that the LED ERR is flashing

15. Put the known weight on the tare

16. Keep pushed the calibration button (or in alternative use digital input signal) until LED ERR switches from flashing to “OFF”
    The module has acquired the known weight value.

17. Power off the module

18. Switch the Dip-Switches SW2-4 to “OFF” and SW2-5 to “ON”. In this way, the module is calibrated.

19. Power ON the module
    If the module is power off during this procedure, calibration setting is lost. Restart the calibration procedure from the first point.

CALIBRATION WITHOUT A STANDARD WEIGHT USING THE CALIBRATION BUTTON

Gross weight (tare + known weight) must not to exceed load cell end scale, to avoid serious damage to the cell.

1. Power off the module before configuring it by Dip-Switches to avoid serious damage due to electrostatic discharges.

2. Switch the Dip-Switches SW2-4 to “ON” and SW2-5 to “OFF”. In this way, factory calibration using calibration button (or digital input). It is possible to acquire tare value by digital input or calibration button.

3. Switch the Dip-Switch SW2-1 to “OFF”. In this way, calibration button for digital input (used during calibration procedure) is enabled and it is possible to acquire tare value.

4. Switch the Dip-Switches SW2-2 and SW2-3 as shown in Dip-Switches table, to select one of the possible modalities of analog output.

5. Switch the Dip-Switches SW2-6, SW2-7, SW2-8 to choose the load cell sensitivity (see Dip-Switch table)

6. Power on the module

7. Put the tare on the load cell

8. Keep pushed the calibration button (or in alternative, only for Z-SG model, use digital input) until LED ERR is “ON”
   The Z-SG / Z-SG-L module has acquired tare value: this value is saved in EEPROM (keep saved when the module is power off).

9. Power off the module

10. Switch the Dip-Switches SW2-4 to “OFF” and SW2-5 to “OFF”. In this way, Z-SG / Z-SG-L module is calibrated.

11. Power on the module
    When calibration procedure is ended, it is possible to calibrate the module by the digital input (only Z-SG model) or by calibration button (after switching SW2-1 to “OFF”: digital input is enabled). If a digital signal commutation (from “0” to “1”) occurs (through screw terminals 1-6), a tare value is saved in RAM memory. This value is erased if the module is power off or when a new digital signal commutation (from “0” to “1”) occurs (through screw terminals 1-6).
    If the module is power off during this procedure, calibration setting is lost. Restart the calibration procedure from the first point.
    Analog output end scale is related to load cell end scale, with the following equation:
    If load cell end scale is equal to 50kg, tare is equal to 10kg and analog output scale range is 0..10V, the maximum net weight is Max net weight = 50 – 10 = 40kg
    When a weight of 40Kg is measured the Analog Output will reach 100% (10 Volts).

Easy-SETUP

Free downloadable from www.seneca.it; the Z-SG/Z-SG-L configuration and the calibration can be performed by RS232 or RS485 bus communication.

Modbus RTU protocol

• The Modbus protocol supported by Z-SG I sthe Modbus RTU protocol.
• The RS485 port Modbus parameters can be configured from Modbus or from Dip switches.
• The RS232 COM port parameters are fixed: Baudrate 2400 baud, Parity None, Delay None, Modbus Station address 1.
• All registers are “Holding register” (Read Modbus function 3) with the convention that the first register is the 40001 address (offset 0).
• The following Modbus functions are supported:
• Read Single Modbus Register (function 3)
• Write Single Modbus Register (function 6)
• Write Multiple Modbus Registers (function 16)
• All values in 32bits are stored into 2 consecutive registers, for example:
• Net Weight in floating point 32 bits is stored into registers 40064 and 40065, the most significant word is the register 40064, the less significant word is the 40065 (default).
• So the 32bits value is obtained by the following relation:
• NetWeight=40064+(40065×2^16)=40064+(40065 ×65536)
• For the floating point values the Z-SG-L model can Swap the Most significant word with the Less significant word.
• For more information about this protocol please refer to Modbus specification website:
• http://www.modbus.org/specs.php

Modbus function code supported

The following Modbus functions are supported:

• Read Holding Register (function 3)
• Read Input Registers (function 4)
• Write Single Register (function 6)
• Write Multiple registers (function 16)

Modbus RTU Register table

• In the following table this abbreviations are used:
• “MS” = Most significant
• “LS” = Less significant
• “MSB” = Most significant Byte
• “LSB” = Less significant Byte
• “MSW” = Most significant Word (16 bits)
• “LSW” = Less significant Word (16 bits)
• “R” = Read only register
• “RW” = Read and write register
• “Unsigned 16 bit” = Unsigned 16 bits register
• “Signed 16 bit” = 16 bit register with sign
• “Float 32 bits” = Floating point single precision 32 bits (IEEE 754) register “0x” = Hexadecimal Value

Generic parameters of Z-SG/Z-SG-L module are shown in the following table.

To choose the number of samples, see the following table.

References

• De facto - Wikipedia
• Standardization - Wikipedia

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