HOLD, IOT, and ErrC Trip on an S100

HOLD, IOT, and ErrC Trip on an S100

HOLD, IOT, and ErrC trips are all very similar. They involve the communication and connection between the IO PCB and the Control PCB. When there is a communication error between these two boards the trip will occur. 



Troubleshooting
The first and easiest recommended check is to disconnect all I/O wires. If there is any noise on the connection this can cause trips. 
  1. Remove all I/O wires. This includes all digital inputs/outputs, analog inputs/output, and communications.
  2. If there is an option card installed such as Ethernet, Extended I/O, etc it is recommended to disconnect this as well. 
  3. Re-apply power and check for the trip condition.

If the above does not work, proceed to the below steps. It is very easy to check and re-seat the cable on the S100. Try the below procedure to check for a connection issue.
  1. Remove front terminal cover.
  2. Remove screw holding down the IO PCB.                                                         
  3. Slide the plastic case which holds the IO PCB down and pull it out. Watch the short white ribbon cable attached.
  4. Remove and re-seat the white cable on the IO PCB side.                                        
  5. If possible, remove the main cover by pressing on the cover tabs with a flat screwdriver. There are 2 on each side.
  6. Remove the main cover and re-seat the same cable on the CPU PCB side.
  7. Reassemble the VFD and apply power. Check if the trip has cleared. If it has not there may be a hardware issue.