Bosch CL400 - Execution of the PLC Program; I;O Map; Communication

Flexible Automation
Central processing unit ZS400
4-32
1070 072 143-101
4.7 ZS400 program execution
Execution of the PLC program
The operator can control the execution of the PLC program by employing
organisation modules (OM) as follows:
D Cyclic OM1
D Cold start, First start OM5
D Restart OM7
D In case of program error OM9
D Control via interrupt input OM10 to OM17
D Timecontrolled OM18 to OM25 and OM42
D Control via system interrupt OM26 to OM41
I/O map
Execution of the I/O map is carried out in a loop from address 0 to the end
address according to the following principle:
D Read in input byte
D Write output byte
Only those I/O addresses are called which are defined via the assign list in
OM2.
The counters for the timers are decremented parallel to the execution of the
I/O map. The accuracy of the timers is therefore determined by the cycle
time.
The interrupts are also processed during the I/O map execution.
Communication
The ZS400 operates the serial interface X31 and the system modules paral
lel to the execution of the PLC program.