3-7
Communications Processor CP 541
EWA 4NEB 812 6188-02
3.4.1
POWER ON
In POWER ON, the CP 541 reacts as shown in the following flowchart.
Step
Flowchart
Explanation
1
Switch on
Power
restored
Whether or not you set the mode
switch from 0 to STOP, or whether
power is restored after a power fail-
ure, the CP 541 reacts in the same
way.
2
CP 541 being initialized;
it executes an internal test.
In the initialization phase, all inter-
nally stored interface data are reset
to reach a defined initial state.
An internal test is simultaneously
executed. During the test, the green
RUN LED flashes at 8 Hz.
3
DB1 in
Yes
The CP 541 checks whether a DB1
is present.
4
DB1 in
EEPROM?
CP 541 tests EEPROM
Yes
No
If no DB1 is stored in the EE-
PROM, it is subjected to a test of
approx. 6 s.
During the test, the green RUN
LED flashes at 8 Hz.
5
EEPROM ok?
No
With the EEPROM test, the CP 541
tests the EEPROM for proper func-
tioning.
6
EEPROM ok?
CP 541 reads in
the default DB1
Yes
If the EEPROM is OK, the CP 541
loads the default DB1 from the op-
erating system.
If an error occurs, DB2 can be read
out but the CP 541 cannot be
switched to the RUN state.
7
CP 541 copies DB1 into RAM
The CP 541 copies DB1 from the
EEPROM into the main memory.
8
STOP state
The CP 541 is in the STOP state.
The RUN LED flashes at 2 Hz.
Power On
Installing and Connecting the CP 541