Siemens SIMATIC ET 200AL, System Manual

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Digital input/Digital output module DIQ 16x24VDC/0.5A 8xM12 (6ES7143-5AH00-0BA0)
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Equipment Manual, 08/2021, A5E38688112-AD
Counting
4
Counting function
Counting refers to the detection and summation of events. The respective counters of the
module detect encoder signals and pulses and evaluate them accordingly, for example:
•
For counting general piece goods up to a maximum limit
• For applications with recurring counting processes
You can control the counting processes with the digital inputs of the digital input / digital
output module belonging to the counter. You can control the digital output belonging to the
counter exactly to defined counter values via comparative results independently of the user
program.
You can parameterize the behavior of the respective counter by means of the functions
described below.
Counter limits
The counter values define the range of values of the counter value than can be used. The
counter limits are configurable and can be modified during runtime using the user program.
The maximum adjustable count limit amounts to 2147483647 (2
31
-1). The maximum
adjustable count limit amounts to -2147483648 (-2
31
).
You can continue or stop counting (automatic gate stop) on violation of a counting limit At
an overflow or underflow of the count value one event bit is respectively set in the feedback
interface. The count value jumps to the respective other counting limit.
Start value
You can configure a start value within the counter limits. The start value can be modified
during runtime with the user program.
Load value
In addition to the parameterization you can influence the counting behavior additionally via
the control interface by means of the load value. Depending on the bit sequence of the load
request (LD_SLOT) contained in the control byte you can load the load value (SLOT) as a
current count value, start value, comparative value or count limit.
If you re-parameterize the module, loaded values are overwritten automatically. Therefore, if
necessary, carry out the adjustment of the values via the control interface again after a re-
parameterization.