Inaccurate AI810 Values
I have an AF100 Network consisting of CI522 (Connected to AC450) ,11 S800I/O Stations (Redundant CI820) with AI810,AO810 I/Os.
Recently I have an Inaccurate Reading of one Temperature Transmitter (Rising from 60 C to 67 C and then come back to 60 C) and the Range is 0-120 C.
So I change the Transmitter,Check the Wiring and Finally I changed the AI810 Card but the Problem is Still exist (Also I measured the 4-20 mA at the Loop and it is Stable and Corresponding to the Real Temperature Value which is 56 C).
Finally I changed the Connection to Another Spare Channel at the Same Module and Now Everything is OK and the Reading is Correct (which is 56 C).
So my Question ,Could the Problem be at MTU TU830V1 or it Could be at the CI820 or Something else?
Sounds like a burned channel on the AI810, this has happened before.
Check that installation is correct - lack of proper grounding has caused similar problem in the past. The S800 installation guide has a comprehensive installation chapter describing earth wire gauges, maximum distance between ground and IO, etc.