Siemens S7-300 - Page 136

Digital modules
8.5 SM 326; DO 8 x DC 24V/2A PM
Fail-safe signal modules
136 Installation and Operating Manual, 01/2010, A5E00085586-10
Diagnostic
message
Error detection Possible causes of the
problem
Corrective measures
Internal supply
voltage of the
module failed
General Internal fault at supply voltage
1L+
Replace the module
Module parameters
not assigned
General No parameters transferred to
module
Assign new module
parameters
Load voltage 2L+, 3L not
connected
Connect 2L+ and 3L+
External fault at load voltage
2L+, 3L+
Replace the module
Defective load
voltage or load
voltage not
connected
General
Short-circuit between P and M Eliminate the short-
circuit
Incorrect module
parameters
General Wrong module Check the module;
replace; assign new
parameters
Overload due to diagnostics
request (SFCs)
Reduce the number of
diagnostics requests
Electromagnetic interference
has exceeded limits
Eliminate the
interference
Time monitoring
activated
(watchdog)
General
Defective module Replace the module
Error in communication
between the CPU and the
module, for example, due to
defective PROFIBUS
connection or electromagnetic
interference in excess of limits
Check the PROFIBUS
connection
Eliminate the
interference
Timeout of data frame
monitoring
Check the monitoring
time parameters
CRC signature error, for
example, due to
electromagnetic interference
in excess of limits.
Eliminate the
interference
Communication
error
General
CPU is in STOP Read the diagnostics
buffer
Electromagnetic interference
has exceeded limits
Eliminate the
interference and cycle
power off/on
EPROM error
RAM error
General
Defective module Replace the module
Internal error in
read / test
sequence
General Defective module Replace the module
Electromagnetic interference
has exceeded limits
Eliminate the
interference
Defective module Replace the module
Processor failure General
Switching rate exceeded Reduce switching rate