Yokogawa 414 Batch Controller - Manual (Page 48)

Counting erratically
This can be caused by lack of shielding on the input.
Shield the input signal with the shield earthed at the Batch
Controller only.
Instrument acting erratically
Erratic operation can be the result of severe electrical
interference. Considerable attention has been given to
designing the Batch Controller to withstand electrical
interference.
However, in extreme cases, loads may be encountered which
are exceptionally inductive and may require additional
protection. One measure is to use an RC Suppression Network
as described in Section 7.
Another remedy for this problem is to use an isolating relay to
switch the load, and use the Batcher to drive the isolating relay.
The isolating relay should be mounted away from the Batcher
and from signal wiring.
No end of batch, pulse output or flow alarm.
This fault is usually caused by lack of a pullup resistor or load
on the output. The outputs themselves have no internal pullups
and rely on an external load.
46 Trouble Shooting