Siemens CPU 948 User Manual

Updating the timers
•• As standard, the timers T 0 to T 255 are updated.
•• If you enter the value "0" in DX 0, no timers are updated, even if
they are included in the program. There is then also no error
message output.
•• Updating is as follows:
Entry ’0’ ’1’ ’2’ ’3’ ’4’ ....
Updating none T0 to
T1
T0 to
T2
T0 to
T3
T0 to
T4
....
Level priorities You can specify different priorities for the program execution levels.
This is achieved either using the default or by specifying DX 0
parameters.
Priorities when "process interrupts via IB 0 = on" is selected
(PROCESS INTERRUPTS level)
These priorities have the following default values in DX 0:
•• timed interrupts: level priority 1 (higher priority)
•• Process interrupts
via input byte IB 0: level priority 2 (lower priority)
You can swap over the priorities in DX 0.
Priorities when "process interrupts via IB 0 = off" is selected
(= processing of system interrupts level INTERRUPTS)
In this mode, the following default priorities are set:
•• timed interrupts: level priority 1 (higher priority)
•• system interrupts:level priority 2 (lower priority)
Parameters for DX 0
CPU 948 Programming Guide
7 - 10 C79000-G8576-C848-04

Siemens CPU 948 Specifications

General

Brand	Siemens
Model	CPU 948
Category	Controller
Language	English