Diagnostics Alarms - Siemens SIMATIC S7-1500 Manual

5.3

Diagnostics alarms

A diagnostics alarm is output for each diagnostics event and the ERROR LED flashes on the
module. The diagnostics alarms can, for example, be read from the diagnostics buffer of the
CPU. 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
Load voltage missing
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 the diagnostics "Underflow", but the module detects the
previous diagnostics "Wire break" and cancels after this error message. The "Underflow"
diagnostics is not detected.
Recommendation: To ensure that all errors get diagnosed, select all check boxes under
"Diagnostics".
Analog Input Module AI 8xU/I HS (6ES7531-7NF10-0AB0)
Manual, 07/2014, A5E03484886-AC
Error code Meaning
6 Impedance of sensor circuit too high
H
Wire break between the module and
sensor
Channel not connected (open)
7 Measuring range violated
H
8 Measuring range violated
H
11 Supply voltage L+ of the module is
H
missing
Interrupts/diagnostics alarms
5.3 Diagnostics alarms
Remedy
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
Connect supply voltage L+ to mod-
ule/channel
31