Ready Steady Eddy

[EddyCurrent]

Today I changed the wiring for the AM882 alarms.

Initially each drive had the alarm set to 'High' so that if a fault occurred the internal alarm contact would close. I have four AM882's so the internal contacts were connected in parallel with an external relay in series fed from 24 volt DC so that if any drive went into fault it would energise the external relay.
This was okay until someone queried it this week highlighting the fact that if any drive lost input power then the external alarm relay would not energise. This is most important where the X axis uses two separate motors.
So using ProTuner I changed the alarm settings to 'Low' and connected the 4 off AM882's internal relays in series along with the external relay, see drawing.
Now the external relay is energised when all AM882's are powered up and healthy, if one goes into fault or loses input power than the external relay will de-energise indicating a fault condition.



For anyone using a PDMX bob FAULT input (J13) they should connect the AM882's as in the diagram using a relay, then connect the normally closed NC contacts of the relay to the PDMX FAULT(J13) input and Gnd(J13)
This means when the relay is energised the PDMX Fault input will be High (floating) and LOW when the relay is de-energised (connected to Gnd)

From the PDMX manual;
"The Fault input provides an interface for external fault detection circuits. This signal is “active low”, meaning that a logic “low” (or ground) indicates a fault condition, and a logic high (or floating) means “all is OK”.