Assembly of a CPU 41x–H
5.3 Status and error displays
S7-400H
System Manual, 03/2012, A5E00267695-11
59
LEDs LINK1 OK and LINK2 OK
When commissioning the fault-tolerant system, you can use the LINK1 OK and LINK2 OK
LEDs to check the quality of the connection between the CPUs.
LED LINKx OK Meaning
Lit The connection is OK
Flashes The connection is not reliable, and the signal is disrupted
Check the connectors and cables
Check whether the fiber-optic cables are installed in accordance with the guidelines in chapter
Installation of fiber-optic cables (Page 346).
Check w
hether the synchroni
zation module works in another CPU.
Dark The connection is interrupted, or there is insufficient light intensity
Check the connectors and cables
Check whether the fiber-optic cables are installed in accordance with the guidelines in chapter
Installation of fiber-optic cables (Page 346).
Check w
hether the synchroni
zation module works in another CPU.
LED MAINT
This LED indicates that maintenance is required. For more information, refer to the STEP 7
Online Help.
Diagnostic buffer
In STEP 7, you can select "Target system -> Module Information" to read the cause of an
error from the diagnostics buffer.
To Next Page
Loading...
