JB2020 (Customer) asked a question.

Edited September 10, 2021 at 2:50 PM
GS Drives Controlled by Productivity via Modbus TCP

Hello,

 

I can get the drive to operate using the GS Write instructions, but the Read instruction will not Auto Read when I toggle the Auto Read rung high. I cannot get RPM or Current readings with Auto Read. I am having to do a Manual Read to try to get these values, but all I get is the frequency.

 

Also, I am unable to write parameters such as the Accel and Decel Time parameters. Parameters 1.01 and 1.02 along with direction. I can change the frequency using data view but I cannot change anything else.

 

I have watched all the Modbus TCP and GS4 videos that Automation Direct has for this. I may have missed something though...

 

Any help on this?

  • 20 answers
  • 1.12K views

  • ADC Community_02 (Automationdirect.com)

    On page B-18 of the GS4 manual it says address 0x0210C is for motor rpm. I would move your tag up to PID feedback signal item in the GSR instruction to see if that works. If yes then that would be a bug in the software GUI that will need to be fixed.

    speed

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  • ADC Community_02 (Automationdirect.com)

    Do you have the drive(s) connected to the Remote I/O internal Ethernet port via a switch?

    • JB2020 (Customer)

      I have one drive connected directly to the PLC remote IO port for testing purposes. However, I plan to have 6 drives connected to the PLC through a switch.

  • Todd Dice (Customer)

    Modbus reads and writes should be unconditional. Productivity has the ability of controlling the polling of the read and writes so they don't all happen at once. I have controlled many drives using this method. If you post your code I can assist on what you need and/or missing.

    • JB2020 (Customer)

      I will post my code on Monday. I have left my office for the weekend already and don’t have access to my computer. (I’m replying to this on my phone)

      • ADC Community_02 (Automationdirect.com)

        "But the Read instruction will not Auto Read when I toggle the Auto Read rung high. I cannot get RPM or Current readings with Auto Read. I am having to do a Manual Read to try to get these values, but all I get is the frequency."

         

        Answer: When you open the instruction you will see the only parameter available for auto read is the Actual Frequency. All other parameters you must do a manual read.

         

        This could be same issue with your GSW parameters due to Run & Jog command frequencies are handled with auto poll. You will need to do a manual write for all other parameters.

         

        gsr1

        Expand Post

      • JB2020 (Customer)

        OK that makes sense! Thanks for that info. Now I would just like some further information on the writing parameters part.

      • Todd Dice (Customer)

        I made one change to your code and that it is the polling offset. Your reads and writes cannot happen simultaneously, thus the offset timing. I changed your read from zero to 50.Screenshot 2021-09-13 072140

      • JB2020 (Customer)

        OK I'll try this and see what happens.

      • ADC Community_02 (Automationdirect.com)

        @JB2020 (Customer)​ This could be same issue with your GSW parameters due to Run & Jog command frequencies are handled with auto poll. You will need to do a manual write for all other parameters.

         

        Try updating the values for accel & decel then do a manual run mode data write.

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