PK100 Not able to communicate over Ethernet/IP on different assembly instance other than 101,100,102

In PK100 controller when i am trying to set the communication with different assembly details it is not comunicating but when i change the assembly instance details to 101,100,102 it works fine.

i have to communicate around 1500bytes. so i am making different LDT with different assembly instance as i think PK100 doesnot support extended Ethernet/IP configuration. i have limitation of 100 signals or 500 bytes in each LDT.

7 Replies

  • I think the limit of 100 signals per LDT is standard it not depends on the PK.
  • In reply to Inocencio Perez:

    Yes..that is correct ...100 signals or 500bytes...
    So as it is increasing more than limit I tried to create another LDT with different assembly instance
    104,103 and 102 as shown in snapshot to accomodate another set of signals but this is not communicating...
    So I am not getting what can go wrong ...(license I was seeing ) but even when I changed the assembly instance details with single instance still it was not working .
    LDT1 104,103,102 is not working
    But same LDT1 101,100,102 IS WORKING

    When I tried with Rockwell PLC it is working ....
  • In reply to Shaswat Raj:

    You need to use the same values in each LDT.
  • In reply to Inocencio Perez:

    100 Signals is what Emerson has chosen for the size of LDT's. This seems to have carried over from the design of Modbus Data sets on Serial cards, and within the new EIOC and PK controller drivers. I wouldn't call it a "Standard". It is simply a design limit to help manage the communication load and spread out the data exchange over multiple calls to the end device. PLC's often use binary values like 64 or 128.

    As for the LDT configuration, the Input and Output size in bytes must match the size of the Input and Output Assembly instances. If they don't match, I don't think it can be successful. You need to know the content of the assemblies in order to map the data into signals.

    Andre Dicaire

  • In reply to Andre Dicaire:

    It's DeltaV standard, so you can go further than that or change that limit...
  • In reply to Inocencio Perez:

    Which means I should use 101,100,102 in each LDT ?
  • In reply to Andre Dicaire:

    That's correct , Bytes are matching when I just change the assembly to 101,100,102 it works perfectly but when I switch back to assembly to 104,103,102 on both PLC and PK100 side it doesn't work.... But the same config work between two different PLC i.e. Compactlogix and Wago PLC I was puzzled if I am missing something in PK100 CONFIG