Measured Value Determination; Overview Of Measuring Functions - 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)
2.2.9

Measured value determination

2.2.9.1

Overview of measuring functions

The following measuring functions are available:
Measurement type (Page 55)
Frequency measurement
Period measurement
Velocity measurement
Measured values and counter values 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 for incremental and pulse encoders
Opening and closing the internal gate defines the period of time during which the count
pulses 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 the internal gate is
closed, the last measured value captured is still returned.
54
Description
The mean frequency is calculated at set measuring intervals on the
basis of the time profile of the count pulses or position value
changes and returned in Hertz as floating point number.
The mean period duration is calculated at set measuring intervals
on the basis of the time profile of the count pulses or position value
changes and returned in seconds as floating point number.
The mean velocity is calculated at set measuring intervals on the
basis of the time profile of the count pulses or position value
changes and other parameters, and returned in the configured unit
of measurement.
Counting, measurement and position detection
Function Manual, 12/2017, A5E32009889-AG