IDEC FS1A Controller - Manual (Page 130)

5-89
Error detection function
Input monitoring and grounding detection
When an error is detected between the dual channel inputs, the SafetyOne changes to the
Protection state and displays "1" on the error LED display. The conditions to be detected as input
errors are shown below.
(1) When an input monitoring error detection time (0.1s) is exceeded during the 2 input conditions
and they do not match (namely ON/OFF or OFF/ON).
(2) When there is an independent condition change of the 1 of the input.
(3) The input circuit of the ON state has gone to ground.
The input LEDs blink and the monitor output (Y
m
) supplies pulses (1Hz), to notify the operator of
the corresponding input. See Fig. 5-8.
Noise detection filter
When the SafetyOne is used in an environment with severe noise, the SafetyOne changes to the
Stop state and displays "9" on the error LED display.
Note: Drive circuit corresponding to the dual channel solid state input (T
n
, T
n+1
) is always OFF.