Hi,
At the facility there is Triconex Tricon System (v10.6) as an ESD system for the Plant. The Shutdown valve is equipped with a solenoid valve and the positioner (Fisher DVC 6030). The Solenoid is powered through a DO card and positioner through an AO card in the Tricon. The Tricon is intermittently giving "External Mismatch Error" for the AO card (3805H) in the Diagnostic and when this alarm appears the AO card goes into fault.
When consulted with Schneider, they came back with the reply as this being due to an external error, meaning some problem in the loop outside the Tricon. So, following steps were taken to check the loop:
1. Check the wiring from the Termination Board to the Positioner.
2. Positioner was checked with the Hart communicator, but that isn't showing any diagnostic error.
3. Even AO card was replaced with the spare new one.
Even now, the alarm is appearing intermittently.
We are still following up with the Schneider to know how does the card generated an alarm, meaning what does the card see in the two wires connected to it that it generates an alarm. Till now what we have received is that the 3 legs inside the Ao module see each other and and based on the mismatch the error is flagged.
However, this doesn't lead to anything that we can validate in the loop, be it in terms of current, voltage or resistance.
Has anybody came across such an alarm and have been able to diagnose, would like to share their experience?
At the facility there is Triconex Tricon System (v10.6) as an ESD system for the Plant. The Shutdown valve is equipped with a solenoid valve and the positioner (Fisher DVC 6030). The Solenoid is powered through a DO card and positioner through an AO card in the Tricon. The Tricon is intermittently giving "External Mismatch Error" for the AO card (3805H) in the Diagnostic and when this alarm appears the AO card goes into fault.
When consulted with Schneider, they came back with the reply as this being due to an external error, meaning some problem in the loop outside the Tricon. So, following steps were taken to check the loop:
1. Check the wiring from the Termination Board to the Positioner.
2. Positioner was checked with the Hart communicator, but that isn't showing any diagnostic error.
3. Even AO card was replaced with the spare new one.
Even now, the alarm is appearing intermittently.
We are still following up with the Schneider to know how does the card generated an alarm, meaning what does the card see in the two wires connected to it that it generates an alarm. Till now what we have received is that the 3 legs inside the Ao module see each other and and based on the mismatch the error is flagged.
However, this doesn't lead to anything that we can validate in the loop, be it in terms of current, voltage or resistance.
Has anybody came across such an alarm and have been able to diagnose, would like to share their experience?