Siemens S5-155U System Manual page 83

Startup and validity check
Insert memory submodule in
CPU (not with the CPU 948)
CPU at "STOP"
Connect power supply
unit
Switch on supply
voltage
PS:
LED "DC 5V"
No
and "DC 24V" on, all
others off
Yes
CPU:
LED "BASP" on
No
LED "STOP" flashing fast
all others off
Yes
CPU general reset
CPU:
LED "STOP" on
No
LED "BASP" on
all others off
Yes
Reset CPU:
Set to "Reset", switch from
"STOP" to "RUN"
Replace memory submodule
CPU:
No
LED "RUN" on,
LED "BASP" off
Yes
Unit O.K.
Figure 4-5 Startup
System Manual
C79000-B8576-C199-03
The following flowchart provides an overview of the sequence for
startup and validity check of a CC with CPU inserted and with no user
program. For the CPU 948, all steps relating to the memory
submodule are skipped.
PS:
No
Correctly wired?
Voltage present?
Yes
Yes
No
Press
LED "RB
RESET
Low" on
LED off
Yes
No
Press
LED "MB
RESET
Low" on
LED off
LED "Fan
Fault" on
LED
"Voltage
Low" on
CPU:
LED "BASP" on
No
LED "STOP" flashing fast
all others off
Yes
Memory sub-
No
Insert memory
module: correctly
submodule correctly
inserted?
Yes
S5-135U/155U Central Controller
Replace bty
compartment
Replace re-
chargeable
battery
Yes
No
Check backup
Fault
bty and replace
corrected
if necessary
Check
Fan
Check load
voltage
connection
Replace CPU
or
repeat startup
Yes
No
Replace
Fault
corrected PS
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