Redundancy Alarm on SIS controllersRed

I have a redundancy alarm "Redundancy: Not Communicating - Secondary Network" occurring multiple times over the course of some minutes in infrequent and inconsistent times on two separate SIS SZ controllers. Each time the alarm will clear 10 seconds later. I have changed out the network port to no avail. Diagnostic monitor indicates the redundancy is good for each controller. Is there anything else to be looked at? I suspect this is being caused by heavy network traffic. Is it possible to put a delay on the controller alarm such that it will only alarm under a sustained alarm condition? Thank you for any assistance.

2 Replies

  • It is not easy to give a good answer without knowing more about your SIS and DCS network layout, so please forgive me if some of my assumptions are not correct.

    1. I am not aware that you can enter or setup a delay on hardware alarms, especially for any SIS hardware. You can only disable the hardware alarms for the SIS controllers (but I do not think you want to do that).

    2. I am assuming that you have looked in your event log for any other network errors around the same time that you get the "Redundancy" error and there were no other alarm (like for the primary not communicating on the secondary network). In that case, is it possible that there is a problem with the SZ controller carrier? Or with the redundant controllers?
    Maybe try changing both the redundant and primary ethernet ports.

    There is one more possibility:
    Depending on your secondary network topology, there might not be anything wrong with the hardware of the controllers, but instead with a component that is before the controller. Maybe a switch port that is the problem or the network port of a previous controller?

    I have to admit, I am grasping at straws, since I have no clue how your network layout looks like.
  • If you go to Hardware Alarms under the controller, it's possible to Enable/Disable and Shelve the alarm, but you can't put a delay.
    Based on your description, it's definitely related to the network, not the controller redundancy. When properly setup, high traffic would not be an issue, but without knowing the architecture, which switches have been used, it's hard to tell, you can do normal troubleshooting like replacing cables, re-clamping connectors, check the F.O. fusion if that's the case, if nothing of that works, you should open a ticket with GSC.