Digital Modules
3-79
Programmable Logic Controllers S7-300 Module Data
A5E00105505-03
Causes of error and remedial action
Table 3-21 Diagnostic Messages of the SM 322; DO 8 x 24 VDC/0.5 A, Causes of Error and Remedial
Action
Diagnostics Mes-
sage
Error Detec-
tion ...
Possible Error Cause Remedy
Wire-break Only with
output to “1”
Open circuit between module
and actuator
Close circuit
Channel not connected
(open)
Disable the “Diagnose
Wire-break” parameter for the
channel in STEP 7
No load voltage Only with
output to “1”
Defective output Replace module
Short-circuit to M Only with
Overload of output Eliminate overload
output to “1”
Short-circuit of output to M Eliminate short circuit
Short-circuit to L+ Always Short-circuit at output to L+ of
module supply
Eliminate short circuit
No external auxiliary
voltage
Always Power supply L+ to module
missing
Feed supply L+
No internal auxiliary
voltage
Always Power supply L+ to module
missing
Feed supply L+
Fuse in module defective Replace module
Fuse blown Always Fuse in module defective Replace module
Watchdog tripped Always Temporary high
electromagnetic interference
Eliminate interference
Module defective Replace module
EPROM error Always Temporary high
electromagnetic interference
Eliminate interference and
switch on/off power supply of
CPU
Module defective Replace module
RAM error Always Temporary high
electromagnetic interference
Eliminate interference and
switch on/off power supply of
CPU
Module defective Replace module