cyclically as the update time. Larger update times smooth uneven measured variables and
increase the measuring accuracyOpening and closing the hardware gate and software gate defines the period of time during
which the count signals are acquired. The update time is asynchronous to the opening of the
gate, which means that the update time is not started when the gate is opened. After the
gate is closed, the last measured value calculated is still returned.The measuring functions have the following measuring range limits:
Table 3- 2 Overview of low and high measuring range limits
Measurement type Low measuring range limit High measuring range limit
Frequency measurement 0.04 Hz 400 kHz *
Period measurement 2.5 μs * 25 s
Velocity measurement Depending on the configured number of "increments per unit" and the "timebase
for velocity measurement"
* Applies to 24 V incremental encoder and "quadruple" signal evaluation
All measured values are returned as signed values. The sign indicates whether the count
value increased or decreased during the relevant time period. For example, a value of -
80 Hz means that the count value decreases at 80 Hz.
Reference
For more information on measuring, refer to the S7-15You can use the digital on-board I/O, e.g. with an incremental encoder, for position detection

with Motion Control. The position input is based on the counting function, which
evaluates the acquired encoder signals and provides them for Motion Control.
In the hardware configuration of the CPU 1512C-1 PN in STEP 7 (TIA Portal), select the
"Position input for Motion Control" mode.nterface between the drives and encoders is referred to as a technology module (TM). In
this context, a technology module (TM) also refers to the digital on-board I/O of the compact
CPU described here.You can configure an external reference signal edge to load the counter with the specified
start value. The following external signals can trigger a synchronization:
● Rising or falling edge of a digital input
● Rising edge of signal N at the encoder input
● Rising edge of signal N at the encoder input depending on the level of the assigned digital
inputhe integrated counter supports 2 comparison values and digital output HSC DQ1. If the
counter or measured value meets the set comparison condition, HSC DQ1 can be set in
order to trigger direct control operations in the process.
Both comparison values can be set in the parameters and can be changed during runtime by
the user program.
Hardware interrupts
If you have enabled a hardware interrupt in the hardware configuration, the counter can
trigger a hardware interrupt in the CPU when a comparison event occurs, if there is overflow
or underflow, at a zero crossing of the counter, and/or at a change of count direction
(direction reversal). You can specify which events are to trigger a hardware interrupt during
operation in the hardware configuration.
Diagnostics interrupts
If you have enabled a diagnostics interrupt in the hardware configuration, the counter can
trigger a diagnostics interrupt if the supply voltage is missing, if there is an incorrect A/B
count signal or lost hardware interrupt.You configure the high-speed counters (HSC) in STEP 7 (TIA Portal).
The functions are controlled by the user program.
in the STEP 7 online help under "Using technology functions > Counting, measuring and
position detection > Counting, measuring and position detection ()"
A detailed description of configuring Motion Control be found in:function manual
● in the STEP 7 online help under "Using technology functions > Motion Control > Motion
Control ()"The user program uses the control interface to influence the behavior of the high speed
counter.
Note
Operation with High_Speed_Counter technology object
The High_Speed_Counter technology object is available for high-speed counting mode. We
therefore recommend use of the High_Speed_Counter technology object instead of the
control interface/feedback interface for controlling the high speed counter.
For information on configuring the technology object and programming the associated
instruction, refer to the , ET 200MP, ET 200SP Counting, measurement and positionhe following table shows the control interface assignment:
Table 3- 3 Assignment of the control interface
Offset from start
address
Parameter Meaning
Bytes 0 to 3 Slot 0 Load value (meaning of the value is specified in LD_SLOT_0)
Bytes 4 to 7 Slot 1 Load value (meaning of the value is specified in