Measured Value Determination - Siemens SIMATIC ET 200SP Manual

Product overview
2.2 Functions
2.2.2

Measured value determination

The following measuring functions are available:
Measurement type
Frequency measurement
Period measurement
Velocity measurement
The measured value and the counter value are available concurrently in the feedback
interface.
Update time
You can configure the interval at which the technology module updates the measured values
cyclically as the update time. Setting longer update time intervals allows uneven measured
variables to be smoothed and increases measuring accuracy.
Gate control
Opening and closing the hardware gate and software gate defines the period of time during
which the counting signals are captured. 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
closing, the last measured value captured continues to be returned.
Measuring ranges
The measuring functions have the following measuring range limits:
Measurement type
Frequency measurement
Period measurement
Velocity measurement
* Applies to 24 V incremental encoders and "quadruple" signal evaluation.
All measured values are returned as signed values. The sign indicates whether the counter
value increased or decreased during the relevant time period.
16
Description
The mean frequency is calculated at set measuring intervals on the
basis of the time profile of the count pulses and returned in hertz as
the floating point number.
The mean period duration is calculated at set measuring intervals
on the basis of the time profile of the count pulses and returned in
seconds as the floating point number.
The mean velocity is calculated at set measuring intervals on the
basis of the time profile of the count pulses and other parameters,
and returned in the configured unit of measurement.
Low measuring range limit
0.04 Hz
1.25 µs*
Depends on the configured number of "increments per unit" and the
"time base for velocity measurement"
Technology Module TM Count 1x24V (6ES7138-6AA00-0BA0)
High measuring range limit
800 kHz*
25 s
Manual, 02/2017, A5E33002339-AB