Hardware Manual

Hardware Manual PCD 1 / PCD 2 Series│Document 26 / 737│Edition EN 15│2008-07-22

Saia-Burgess Controls AG

PCD1.M1x0 and PCD1.M1x5 operating states

CPUs and expansion housings

3

3.10 PCD1.M1x0 and PCD1.M1x5 operating states

The CPU can assume the following operating states:

START, RUN, CONDITIONAL RUN, STOP and HALT

The display uses 3 LEDs: SUPPLY 24 VDC LED yellow

RUN LED yellow

ERROR LED red

The “SUPPLY 24 VDC” LED shows that the electrical supply is working.

The RUN and ERROR LEDs together show the operating state of the CPU:

STARTRUN COND. RUNSTOPHALTRESET

RUN ●/○ ● ●/○○ ○ ○ ●

ERROR ●/○/○ 1) 1) 1) 1) ●

1) An ERROR may be signalled by the LED in operating states RUN, CONDITIONAL RUN, STOP or HALT. In the

event of an error, the LED only lights up if there is no XOB 13 programmed to deal with this error.

● LED on

●/○ LED flashing

○ LED off

START Self-diagnosis for approx. 1s after switching on or after a Restart

RUN Normal processing of the user program after START. Where a

programming device is connected in PGU mode (e.g. PG5 in PGU mode),

the CPU automatically goes into the STOP state and not the RUN state;

this is for safety reasons

COND. RUN Conditional RUN state A condition has been set in the debugger (RUN

until..), which has not yet been met

STOP The STOP state occurs in the following cases:

• Programming device in PGU mode connected when CPU switched on


• PGU stopped by programming device


• Condition for a COND. RUN has been met

HALT The HALT state occurs in the following cases:

• HALT instruction processed


• Serious error in user program


• Hardware fault


• No program loaded


• No communication module on a S-Bus PGU or Gateway Master port

RESET The RESET state has the following causes:

• Supply voltage too low


• Firmware not starting up