IDEC FS1A Controller - Manual (Page 132)

5-91
Error detection function
Input monitoring
When an error is detected at the inputs, the SafetyOne changes to the Protection state and
displays "1" on the error LED display. The condition to be detected as input error is shown below.
(1) When input monitoring error detection time (0.5s) is exceeded while both of the 2 input
conditions are ON.
The input LEDs blink and the monitor output (Y
m
) outputs pulses (1Hz), to notify the operator of
the corresponding input. See Fig. 5-10.
Short circuit detection
When an input error, such as a short circuit, or a circuit failure, is detected, the SafetyOne
changes to the Stop state and display "2" on the error LED display.
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.
Warning
Safety check signals (pulses signals) are supplied from the drive circuits (T
n
) to diagnose
connected safety devices and input circuits. Safety check signals can not be used as power for
connected devices.
Note: Drive circuit “T
n+1
” is always OFF.