Plc Md For The Operating System (System Data) - Siemens SINUMERIK 840C Installation Instructions Manual

09.95
8.2

PLC MD for the operating system (system data)

2
Default value
1
3
Default value
1
4
Default value
1
You can use the organization blocks OB 5, OB 6 and OB 7 for time-controlled program
execution.
You can vary the time base by specifying a factor. This factor is specific to the block:
Normal time
Blocks
base
OB 5 2.5 ms
OB 6 10 ms
OB 7 100 ms
You must not specify zero as a factor.
If you want to use OB 5, set PLC MD 6051.0 to 0 to enable OB 5 to be invoked. See also
PLC MD 6050 (enable block for processing) and PLC MD6048 (processing delay).
5
Default value
64
The processing of timers causes a certain amount of work for the PLC operating system.
Should a user program require e.g. only timers 1 to 20, entry of the number 20 tells the
operating system that it should process only these timers. This saves processor time, and can
even reduce the PLC cycle time.
An entry of "-1" disables all timers.
The extension to 255 is only possible with option N05; otherwise 127 timers are available.
© Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
8.2 PLC MD for the operating system (system data)
Time base for calling OB 5
Lower input limit Upper input limit
+1
Time base for calling OB 6
Lower input limit Upper input limit
+1
Time base for calling OB 7
Lower input limit Upper input limit
+1
Factor
1 to 3
1 to 9
1 to 255
Last STEP 5 timer
Lower input limit Upper input limit
-1
6FC5197- AA50
8 PLC Machine Data (PLC MD)
Units
3 2.5 ms
Units
9 10 ms
Units
255 100 ms
Units
+255
DB 60
DW 2
DB 60
DW 3
DB 60
DW 4
DB 60
DW 5
–
8–3