How do I drop one Modbus node address

Ignition
1

Dear all,

May i know how do i drop one modbus node address if the modbus deivce is fault because it is causing the other modbus devices in the same loop to be intermittent in ignition?

Thank you in advance

2

There is no simple way with the IA native driver. The best you can do is:

  • Choose one tag in that node to be your "canary",

  • Make a boolean expression tag that uses the isGood() expression function to signal when the canary tag is OK,

  • Make a "driven" tag group that uses the boolean expression as its control, and zero as the undriven pace (which disables polling), and

  • Change all other tags in that node to use that tag group.

  • Set a short response timeout in the device settings, so that one tag fails quickly every time it is checked.

If that is too much trouble, consider using my alternate modbus driver, at it has broken node detection built-in. (You would still use a short response timeout.)