Siemens S7-1500 Manual page 22

Interrupts/diagnostic alarms
5.1 Status and error displays
Meaning of the LED displays
The tables below explain the meaning of the status and error displays.
LED RUN/ERROR
Table 5- 1 RUN/ERROR status and error displays
LED
RUN ERROR
Off Off
Flashes Off
On Off
On Flashes
Flashes Flashes
LED CHx
Table 5- 2 CHx status display
LED CHx
Off
On
On
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Meaning
Voltage missing or too low at backplane bus.
The module starts and flashes until the valid
parameter assignment is set.
Module is ready.
Indicates module errors (at least one error at
one channel, e.g., wire break).
Hardware defective.
Meaning
0 = Status of the input signal.
1 = Status of the input signal.
Diagnostics: Wire break or hardware interrupt
lost
Switch on the CPU and/or the system pow-
•
er supply modules.
Verify that the U connectors are inserted.
•
Check to see if too many modules are in-
•
serted.
---
Evaluate the diagnostics data and eliminate the
error (e.g., wire break).
Replace the module.
---
---
Check the wiring. When using simple switches,
disable diagnostics or connect a resistor to the
encoder contacts.
Digital input module DI 16x24...125VUC HF (6ES7521-7EH00-0AB0)
Remedy
Remedy
Manual, 12/2016, A5E35681478-AC