Devicenet communication

Hello All,

             Having 15 nodes connected through devicenet communication 11 parker nodes,1AB module,1BBS and 2 nos parker drive 160kw and 4.2kw end terminator at 4.2kw drive..

whenever we start 160kw drive the whole devicenet communication fails,and whithout connecting to 160kw drive the communication is healthy anyone can helpme out..

12 Replies

  • There may be a chance that the motor influences the communication by magnetic fields.
    When this is the case, you should give the DeviceNet wire a different route / location / magnetic isolation.
    When possible you should connect a scope to the communication wire, whatch the communication and signal quality (for square pulses), and see whether the signal quality changes when starting the pump / when the pump has started.
  • In reply to Maarten van der Waal:

    When you say you start the drive, does this mean you are starting it over DeviceNet?
  • In reply to harnettw:

    The start command to drive over device net communication
  • In reply to Maarten van der Waal:

    Tried separate routing to drive communication card and placed end Terminator also same happens the drive gets started but communication fails once the drive starts
  • In reply to Aravinthkalaimani:

    Let do some troubleshooting for your segment. Make sure your terminators is from end to end and all your devices are in the middle. Also check to see if your terminators are still good. Sometime these goes bad and will allow extreme noise which will cause this issue.
    I recommend that you go to DeltaV Diagnostics and look at the DeviceNet card statistics. I would expect the comm errors is incrementing pretty fast with all your devices. I would reset those statistics and look at your card level, and device level. I would expect one of those device(s) has a good number of comm errors incrementing. Isolate them and see if that spur cable is bad or the device is bad. Once you have remove all your bad devices on your segment, there should not be any bad comm errors incrementing. I have seen where a drive was putting extreme noise into the segment when it is on. It was due to the manufacturer did not isolate the DeviceNet comm card and the main drive. They had to redesign it.
    Check the baud rate you have setup the DeltaV DeviceNet card. Is it running at 500 kbit Baud rate or 125kbit? The faster you run the system, the shorter distant your cable can be. Some people design their segment to run at 125 Kbit but later change it to 500 Kbit and causes comm issue.
    Another thing, make sure these devices you have are all in compliance with the ODVA standard and should be on the ODVA website as an approved device.

    Overall, it sound like this is a drive issues if he is the only one causing the shutdown. How many of these drives do you have and are they all casuing the same issue?
  • In reply to Tinh Phan:

    Tinh's suggestion that the drive's use of DeviceNet may be the cause.
    If possible, remove power from the DeviceNet card in the drive, or remove it from the drive but leave it connected to the DeviceNet cable leaving it near its installed location. Check your DeviceNet segment using DeltaV Diagnostics like Tinh said. Then start the drive manually (not through DeltaV) and recheck your DeviceNet segment using DeltaV Diagnostics.
    This will help determine if it is the environment and cable, or if it is the card and drive. If you see no change on the DeviceNet segment, with the card off/separated, then it is the card and drive as Tinh had experienced. If you do see issues, then it is your cable shielding or terminator.

    Sal Salamone

  • In reply to Sal Salamone:

    Sa said above started drive in manual mode at 0 rpm with device net communication connected immediately all the devices in DeltaV network lost communication, again resetted communication and started drive at 10 rpm in auto mode the communication lost for exact 2 min and restored measued voltage while starting at 10 rpm dropped to 11v and resumed to 24 v and CAN H CAN L varied from 0.5 to 0.9 V suspecting drive control board having problem.
  • In reply to Tinh Phan:

    We have 16 drives all of eurotherm make only this drive causing communication issue, while trouble shooting connected only drive in network and removed other 14 nodes changed end Terminators at drive and controller side,baud rate is set to 125 k bit in network already started drive and had same problem..checked for cable short circuits at each nodes all were good without connecting drive communication was good
  • In reply to Aravinthkalaimani:

    Have you gone through troubleshoot using DeltaV Diagnostics checklist I mentioned earlier. This will save a lot of time. Helps isolate where the issue is at or identify the whole segment might be compromise. Good Luck
  • In reply to Aravinthkalaimani:

    Have you by change swapped interface cards with a working drive? I think you have the issue identified.

    Sal Salamone

  • In reply to Sal Salamone:

    Yes changed interface card and started drive no issues. Thank you
  • In reply to Aravinthkalaimani:

    Great! Glade you identified and solved the issue.