Chapter 7 Discrete I/O Slave Unit Specifications
7-6
(2) I/O status display
Table 7.7 I/O LED status
Unit Description
Action
LED stays lit.
Check whether or not the external device
is continually on.
LED does not turn on.
Check whether the terminal block has
come loose, or check whether the external
devices are functioning.
LED stays lit although there is no input signal.
Input
LED does not turn on although there is an input
signal.
Replace the unit.
LED stays lit.
LED does not turn on.
The load is functioning although the output is not
specified.
Replace the unit.
Output
The load is not functioning although the output is
specified.
Check whether the terminal block has
come loose, or check whether the external
load is functioning.