Siemens Simatic S7-1500 / ET 200MP - Page 28

Diagnostic alarms
5.1 Status and error displays
Digital input module DI 64x24VDC SNK/SRC BA (6ES7521-1BP00-0AA0)
Equipment Manual, 07/2020, A5E48025116-AA
27
Meaning of the LED displays
The following table explains the meaning of the status and error displays.
RUN and ERROR LED
Table 5- 1 Status and error displays RUN and ERROR
LED
Meaning Remedy
RUN
ERROR
Off
Off
Voltage missing or too low at backplane bus
• Switch on the CPU and/or the system power
supply modules.
• Verify that the U connectors are inserted.
• Check whether too many modules are in-
serted.
Flashes
Off
Module starts up
---
On
Off
Module is ready
Flashes
Flashes
Hardware defective
Replace the module.