Specific problems, 6 specific problems – IAI America SCON-C User Manual
Page 240
222
Appendix
5.6 Specific
Problems
I/O signals cannot be exchanged with the PLC.
Cause: [1] The 24-V I/O power supply is connected in reverse.
(In this case, the input circuits are not affected, but the output circuits will be damaged.)
[2] If the problem is with an output circuit, a circuit component may have been damaged due to a
large load that caused the current flowing into the circuit to exceed the maximum current.
[3] Contact failure in the connector or relay terminal block on the PLC end.
[4] Contact failure between the female pins in the flat cable connector and the male pins on the
controller due to expanded female pins.
Action: Check the connection condition of the power supply and connector, as well as the load on the
output side.
If the cause is identified as [1] or [2], the controller must be replaced. If there is a possibility of [4],
the flat cable must be replaced. Please contact IAI.
Warning: When performing a continuity check of the flat cable, pay due attention not to expand the female
pins in the connector. It may cause contact failure and disable normal operation of the controller.
The ALM lamp illuminates when the power is input.
(An alarm is present.)
* An alarm is present. Connect the PC or teaching pendant, check the nature of the alarm, and remove the
cause.
The EMG lamp illuminates when the power is turned on.
(This condition indicates that an emergency stop is actuated.)
[1] Check if the emergency stop switch on the operation panel is depressed.
[2] Check if pin 4 (EMG-) of the system I/O connector is unconnected.
(Refer to 2.2, “Name and Function of Each Part.”)
The SV lamp does not illuminate when the servo ON signal is input after the power was input.
(The servo does not turn ON.)
Cause: [1] Contact failure of the flat cable
[2] The operation mode status is “MANU.”
[3] Faulty controller
Check the servo ON signal (SON) on the I/O monitor screen of the PC or teaching pendant.
If the signal is input, probably the controller is faulty. Please contact IAI.