Specify Measured Value (High_Speed_Counter) - Siemens SIMATIC ST-1500 Function Manual

3.5.7

Specify measured value (High_Speed_Counter)

Measured variable
This parameter is used to specify the measured variable (Page 55) to be provided by the
technology module. The technology object displays the measured value at the output
parameter MeasuredValue.
You can select from the following options:
Measured variable Meaning
Frequency The measured variable shows the number of increments
(default) per second. The value is a floating point number (REAL).
The unit is Hz.
Period The measured variable is the average period between
two increments. The value is an integer (DINT). The unit
is s.
Velocity The measured variable is a velocity.
Examples of a velocity measurement can be found in the
explanation of the "Increments per unit" parameter.
Update time
By configuring the update time (Page 55) in milliseconds, you can specify the time interval
between two measured value updates.
The update time and the signal type effect the accuracy of the measurement. In the case of
update times of at least 100 ms, the effect of the signal type is negligible.
In the case of update times of less than 100 ms, you achieve maximum measurement
accuracy using the following signal types:
● Incremental encoder (A, B phase-shifted) with Signal evaluation "Single"
● Incremental encoder (A, B, N) with Signal evaluation "Single"
● Pulse (A) and direction (B)
● Pulse (A)
In the case of other signal types, measurement accuracy depends on the encoder and cable
used.
If you enter "0", the measured value is updated once per module-internal cycle. Up to three
decimal places can be entered. A value from 0.0 to 25000.0 is permissible. The default
setting is "10.0".
Counting, measurement and position detection
Function Manual, 12/2017, A5E32009889-AG
Using the High_Speed_Counter technology object
3.5 Configuring the High_Speed_Counter
Additional option-specific parameters
Update time
•
Update time
•
Update time
•
Time base for velocity measurement
•
Increments per unit
•
115