Siemens SIMATIC BATCH User Manual

The more ROPs, EPHs or transitions included in the recipe, the longer the time needed to
process the recipe. To allow the configuration engineer of the process cell to set the optimum
allocation of time for running the process (actuators, sensors, process logic etc.) and time for
processing recipes, there are two parameters in UNIT_PLC:
● Max_CycleRun IN
Maximum time per processing cycle that may be used to process batch control The default
value is 25 ms and the input of the block is not visibly interconnected.
● QAvgRecProcTime INOUT
Average time per processing cycle that is currently used to process batch control. Two
measured values, the average calculated time of the last cycle + measured value of the
current cycle are taken into account for each calculation.
Examples are provided below to show the two parameters. This assumes that only one unit is
fitted in the AS.
Example 1: UNIT_PLC installed in OB32 (1000 ms watchdog interrupt), suitable parameter assignment
MaxCyclRun is set to 50 ms Assessment
approx. 1/20 processing time for batch processing
approx. 19/20 processing time for processing processes in the
OB 32 and other OBs
QAvgRecProTime = 30 to 40 ms OK
QAvgRecProTime = 40 to 50 ms Still OK
QAvgRecProTime = 50 to 60 ms* Not OK
Example 2: UNIT_PLC installed in OB32 (1000 ms watchdog interrupt), suitable parameter assignment
MaxCyclRun parameterized at 100 ms Assessment
approx. 1/10 processing time for batch processing
approx. 9/10 processing time for processing processes in the
OB 32 and other OBs
QAvgRecProTime = 80 to 90 ms OK
QAvgRecProTime = 90 to 100 ms Still OK
QAvgRecProTime = 100 to 110 ms* Not OK
Example 3: UNIT_PLC installed in OB35 (100 ms watchdog interrupt), acceptable parameter assignment
MaxCyclRun parameterized at 30 ms Assessment
approx. 1/3 processing time for batch processing
approx. 2/3 processing time for processing processes in the
OB 35 and other OBs
QAvgRecProTime = 10 to 20 ms OK
QAvgRecProTime = 20 to 30 ms Still OK
QAvgRecProTime = 30 to 40 ms* Not OK
Example 4: UNIT_PLC installed in OB35 (100 ms watchdog interrupt), bad parameter assignment
MaxCyclRun is set to 50 ms Assessment
approx. 1/2 processing time for batch processing
approx. 1/2 processing time for processing processes in the
OB 35 and other OBs
QAvgRecProTime = 30 to 40 ms OK
QAvgRecProTime = 40 to 50 ms Still OK
QAvgRecProTime = 50 to 60 ms* Not OK
* Recipe processing cannot be undertaken in a processing cycle but must instead be split
over two processing cycles. The system thereby extends the batch runtime by one processing
Engineering
7.1 Basic engineering for PCS 7
SIMATIC BATCH V8.2
Operating Manual, 02/2016, A5E35958174-AA 147

Siemens SIMATIC BATCH Specifications

General

Brand	Siemens
Model	SIMATIC BATCH
Category	Control Systems
Language	English