Diagnostics Alarms - Siemens SIMATIC S7-1500 Manual

5.3

Diagnostics alarms

A diagnostics alarm is generated and the ERROR LED flashes on the module for each
diagnostics event. The diagnostics alarms can be read out in the diagnostics buffer of the
CPU, for example. You can evaluate the error codes with the user program.
If the module is operated distributed with PROFIBUS DP in an ET 200MP system, you have
the option to read out diagnostics data with the instruction RDREC or RD_REC using data
record 0 and 1. The structure of the data records is available on the Internet in the "Manual
for interface module IM 155-5 DP ST (6ES7155-5BA00-0AB0)".
Table 5- 5 Diagnostics alarms, their meaning and corrective measures
Diagnostics alarm
Wire break
Overflow
Underflow
Parameter assignment
error
Load voltage missing
Reference channel
error
Common mode error
Diagnostics alarms with value status (QI)
If you configure the module with value status (QI), the module always checks all errors even
if the respective diagnostics is not enabled. But the module cancels the inspection as soon
as it detects the first error, regardless if the respective diagnostics has been enabled or not.
The result may be that enabled diagnostics may not be displayed.
Example: You have enabled "Underflow" diagnostics, but the module detects the "Wire
break" diagnostics first and aborts after this error message. The "Underflow" diagnostics is
not detected.
Recommendation: To ensure that all errors can be diagnosed reliably, select all check boxes
under "Diagnostics".
Analog input module AI 8xU/I/RTD/TC ST (6ES7531-7KF00-0AB0)
Manual, 09/2016, A5E03484864-AD
Error code Meaning
6 Impedance of encoder circuit too
H
high
Wire break between the module and
sensor
Channel not connected (open)
7 Measuring range violated
H
8 Measuring range violated
H
10
The module cannot evaluate
•
H
parameters for the channel
Incorrect parameter assignment
•
11 Supply voltage L+ of the module is
H
missing
15 Invalid reference temperature for the
H
used TC channel with compensation
118 Valid common mode voltage ex-
H
ceeded
Causes when a 2WT is connected,
e.g.:
Wire break
•
Galvanic connection to M
•
Interrupts/diagnostics alarms
Solution
Use a different encoder type or modify the
wiring, for example, using cables with
larger cross-section
Connect the cable
Disable diagnostics
•
Connect the channel
•
Check the measuring range
Check the measuring range
Correct the parameter assignment
Connect supply voltage L+ to mod-
ule/channel
Check the resistance thermometer. For
the compensation with data record, re-
store communication to the mod-
ule/station.
Check the wiring, e.g. sensor ground
connections, use equipotential cables
ANA
5.3 Diagnostics alarms
41