Transmission Error: Timeout (Watchdog Time 1 Or 2 Expired) 78 D; Module Is Defective; Watchdog Tripped; Short-Circuit To L - Siemens SIMATIC S7-1500 Manual

Interrupts/diagnostic messages
6.3 Diagnostic alarms
Diagnostic alarm
Transmission error: Incon-
sistent data (CRC error)
Transmission error: Timeout
(watchdog time 1 or 2 ex-
pired)

Module is defective

Watchdog tripped

Short-circuit to L+

48
Fault Meaning
code
77 The firmware of the F-module has de-
D
tected a CRC error.
Possible causes:
The communication between the F-
•
CPU and F-module is disturbed.
Impermissibly high electromagnetic
•
interference is present.
An error occurred in the sign-of-life
•
monitoring.
78 The firmware of the F-module has de-
D
tected a timeout.
Possible causes:
The F-monitoring time is set incorrect-
•
ly.
A bus fault is present.
•
256 Possible causes:
D
Impermissibly high electromagnetic
•
interference is present.
The F-module has detected an inter-
•
nal error and has reacted in a safety-
related manner.
259 Possible causes:
D
Impermissibly high electromagnetic
•
interference is present.
The F-module has detected an inter-
•
nal error and has reacted in a safety-
related manner.
261 Short-circuit to L+ can mean:
D
The output cable is short-circuited to
•
L+.
The capacitive load between the
•
channels is too high (for example, due
to cable length)
You must eliminate the error within 100
hours; otherwise, the F-module is perma-
nently passivated and an acknowledg-
ment is no longer possible.
•
•
•
•
•
•
•
•
•
•
Digital output module F-DQ 8x24VDC/2A PPM (6ES7526-2BF00-0AB0)
Remedy
Check the communication connec-
tion between the F-module and
F-CPU.
Eliminate the electromagnetic inter-
ference.
Check the parameter assignment.
Ensure that communication is func-
tioning correctly.
Eliminate the interference. The
module must then be pulled and
plugged, or the power switched
OFF and ON.
If the F-module cannot be put back
into operation, consider replacing it.
Eliminate the interference. The
module must then be pulled and
plugged, or the power switched
OFF and ON.
If the F-module cannot be put back
into operation, consider replacing it.
Correct the process wiring.
Increase the test times (dark, light,
switch-on tests).
Manual, 01/2016, A5E03858037-AA