Siemens S5-155U System Manual page 178

System Manual
C79000-B8576-C199-03
ADF LED
on The user program has referenced an I/O address in the
process image under which no module is inserted.
ZYK LED
on The maximum cycle monitoring time has been
exceeded.
BASP LED
on Command output is inhibited and the digital outputs will
be directly switched to the safe state.
A detailed description of interrupt and error handling can be found in
the CPU 928B Programming Guide.
LED LED Cause
SI 1 SI 2
on on No communication possible at both interfaces.
Internal error.
on off SI1:
No communication possible. Internal error.
SI2: If used, interface is initialized and ready.
off on SI1: Interface is initialized and ready.
SI2: No communication possible.
Wrong interface submodule inserted or wrong
parameters for interface or internal error.
off off First interface and, if used, second interface are
initialized and ready.
CPU 928B
5
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