Recording Of Count Signals; Counting With Incremental Or Pulse Encoder - Siemens SIMATIC ST-1500 Function Manual

The basics of counting, measurement and position detection
2.2 Basics of counting, measuring and position input (TM Count, TM PosInput, Compact CPU)
2.2.3

Recording of count signals

2.2.3.1

Counting with incremental or pulse encoder

Counting refers to the recording and adding up of events. The counters of the technology
modules capture and evaluate pulse and incremental signals. The count direction can be
specified using encoder or pulse signals or through the user program.
You can control counting processes using the digital inputs of the technology module. You
can switch the digital outputs exactly at defined counter values, regardless of the user
program.
You can configure the response of the counters using the functionalities described below.
Counter limits
The counter limits define the counter value range used. The counter limits are configurable
and can be modified during runtime using the user program.
The highest counter limit that can be set is 2147483647 (2
can be set is –2147483648 (–2
You can configure the response of the counter at the counter limits:
● Continue or stop counting upon violation of a counter limit (automatic gate stop)
● Set counter value to start value or to opposite counter limit upon violation of a counter
limit
Start value
You can configure a start value within the counter limits. The start value can be modified
during runtime by the user program.
The technology module can, as configured, set the current counter value to the start value
upon synchronization, upon Capture function activation, upon violation of a counter limit or
when the gate is opened.
Gate control
Opening and closing the hardware gate and software gate defines the period of time during
which the counting signals are captured.
The hardware gate is controlled externally via a digital input of the technology module. The
software gate is controlled via the user program. The hardware gate can be enabled through
parameter assignment. The software gate (bit in the control interface of the cyclic I/O data)
cannot be disabled.
22
).
31
–1). The lowest counter limit that
31
Counting, measurement and position detection
Function Manual, 12/2017, A5E32009889-AG