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edited July 2018 in Programming
I am trying communication between the PLC and Robotiq Universal Controller .

When reading is performed using the command of FC 03
Error response comes back.

The address specifies 0x03E8 (1000), but is it wrong?
Please give me the correct answer address.

Please also tell me the address to direct to the robot at the same time

Best Answers

  • YOSHIHISAYOSHIHISA Posts: 5 Apprentice
    Answer ✓
    Thank you for responding the other day.
    Thanks to that, the robot hand is running smoothly.

    I have one more question.

    When moving the hand, first issue an activation command from the PLC
    Even if the communication is interrupted now, although it starts to move, even if the activation operation
    It is control that requires.
    Is it possible to control without this activation operation?

    What is the state if activation is required?

    Thank you for your consideration.


  • Etienne_SamsonEtienne_Samson Beta Tester Beetle, Wrist Camera URCap 1.3.0, Vacuum Beta tester Posts: 419 Handy
    @YOSHIHISA have you looked into the controller online manual? Look into section 4 of the manual. Without anything plug, you should at least be able to read Byte 2 bit 4 to 7 who will return the fault status. Should return 0x00. What have you plugged into the controller?

    Have you also double checked your IP address and communication settings? They can be found in section 3.5 of the manual
    Etienne Samson
    Technical Support Director
    +1 418-380-2788 ext. 207
    [email protected]
  • YOSHIHISAYOSHIHISA Posts: 5 Apprentice
    Thank you for your reply immediately.

    I am using modbus tcp type Universal Controller.
    Since I have confirmed the operation using Robotiq User Interface test software
    I think that wiring is not wrong.

    I also confirmed the IP address with PING

    I am communicating programming by referring to Chapter 4 of "2F - 85 & 2F - 140 - Instruction Manual".
    4.7.2. Read holding registers (FC03)
    Request is: 09 03 07 D0 00 02 C5 CE
    The controller
    I made an error response when I made this request.

    When register 0x07D0 is changed to 0x0200 or less
    A normal response comes back.

    So I thought that the read address is different between RTU and TCP.
    As response comes back, I think that protocols etc. are done normally.

    Please tell me the difference between RTU and TCP.

    Thank you for your consideration.

  • louis_bergeronlouis_bergeron Posts: 94 Handy

    Modbus RTU is a Fieldbus protocol running over a serial com port.  It could be RS-232, RS-422 or RS-485.  It's the protocol running inside the gripper and we use an RS-485 line.  Modbus TCP is derived from this protocol but running over an Ethernet connection.  The protocol is slightly different.  It's the goal of the Universal controller to convert the Modbus TCP protocol (PLC side) to the Modbus RTU protocol (gripper side).  What is explained in the Gripper manual, it's the Modbus RTU protocol the gripper is using.  If you would like to program yourself a standard Fieldbus protocol, you can find documentation about how they work on the web, but it absolutely not required.  Normally, PLC have a lot of Fieldbus master device available like EtherCAT, Ethernet/IP, Profinet, Modbus TCP and then with the according Universal controller, gripper registers are then directly accessible in the PLC.  Only the Fieldbus need to be configured.  Fieldbus configuration file can be found on support web page here:  https://robotiq.com/support/2f-85-2f-140.  If you PLC support Modbus TCP then you are supposed to simply configure the registers of the gripper.  If the PLC doesn't support the Modbus TCP, a suggest you to change to a Fieldbus your PLC support.  If you absolutely want to program yourself this standard protocol.  You can find some information on this website regarding the Modbus TCP protocol:  http://www.simplymodbus.ca/TCP.htm

    Louis Bergeron
    Integration Coach
    [email protected]
  • YOSHIHISAYOSHIHISA Posts: 5 Apprentice
    Thank you for quick response.

    I can not find the modbus TCP configuration file on this website
    I can not change to a Fieldbus , because the PLC does not support only modbus TCP.

    If you do not have a modbus TCP configuration, do you know the address of the input output register, do you have any reference somewhere?

    The PLC side supports modbus TCP, and it seems that reading and writing are possible if only the address is known.

    That's all, thank you very much.
  • YOSHIHISAYOSHIHISA Posts: 5 Apprentice
    Thank you for your reply immediately.

    It has not worked well yet 
    I'm thinking of trying a method to directly connect to PLC using RS 485 directly without using a universal controller.
    Is it possible to connect directly to PLC?
    Do I need a universal controller compatible with modbus RTU?

    In that case, will I refer to "2F - 85 & 2F - 140 - Instruction Manual" as a reference?
    If I connect directly, is modbus RTU communication?
    Is the slave ID according to the instruction manual?
    Are the communication speed settings as well as manual?

    Thank you for your consideration.
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