Siemens SIMATIC S7-1500 Manual page 75

Interrupts/diagnostic messages
5.1 Status and error display
Meaning of the LED displays
The following tables explain the meaning of the status and error displays. Remedial
measures for diagnostic alarms can be found in section Diagnostic alarms (Page 76).
Table 5- 1 Status and error displays RUN/ERROR/MAINT
LEDs
RUN ERROR
Off Off
Flashes Off
On Off
On Flashes
Flashes Flashes
Table 5- 2 PWR/24VDC/5VDC/ERROR status displays
LEDs
PWR 24VDC/
5VDC
Off Off
Off Off
On On
On Off
On Off
Only when diagnostic interrupts enabled
1
74
MAINT
Missing or insufficient voltage on the
backplane bus
Off
Technology module parameters not set ---
Off
Technology module parameters set
and no module diagnostics
Off
Technology module parameters set
and module diagnostics (at least one
Off
error is present)
Hardware or firmware defective
Flashes
ERROR
Supply voltage too low or missing
Off
Flashing
1
Supply voltage is present and OK
Off
Short-circuit or overload at the encoder
supply
Off
Flashing
1
Meaning
Meaning
Technology module TM PosInput 2 (6ES7551-1AB00-0AB0)
Remedy
Switch on the CPU and/or the system
power supply modules.
Check whether the U connectors are
•
plugged in correctly.
Check whether too many modules
•
are plugged in.
Evaluate the diagnostic alarms and
eliminate the error.
Replace the technology module.
Remedy
Check the supply voltage.
•
Make sure that the front connector is
•
correctly inserted.
---
Correct the encoder wiring.
•
Check the loads connected to the
•
encoder supply.
Check the supply voltage.
•
Manual, 06/2018, A5E03982218-AB