Notes On Operation; Restart Characteristics; Checking The Module - Siemens SIMATIC S5 CP 521 Manual

CP 521
4

Notes on Operation

4.1

Restart Characteristics

The CP 521 performs a restart operation when the power supply is restored
(POWER ON).
The restart procedure consists of
• Deleting the message buffer
•

Checking the module ( 4.1.1)

• Memory submodule evaluation ( 4.1.2)
• Clock test ( 4.1.3)
If errors occur during the restart procedure, the module sends an error message
to the CPU in byte 0 of the PII* "Module status" (print mode
7.5.3).
4.1.1 Checking the Module
In this part of the restart procedure, the proper functioning of the hardware is
checked. Errors are provided with the appropriate number in byte 0 of the PII
"Module status" and can be evaluated in the control program or with the
programmer.
Error number
in byte 0
1X Clock fault
H
8X Hardware fault
H
X7 No backup battery
H
X: may have different values
GWA 4NEB 812 6030-02b
Table 4-1. Module Errors
Error
Replace module
Replace module
Insert new battery
Notes on Operation
6.6, ASCII mode
Remedy
4-1