Siemens SIMATIC ST-1500 Function Manual page 62

2.2 Basics of counting, measuring and position input (TM Count, TM PosInput, Compact CPU)
Velocity measurement
The normalized frequency is output as the measured value in velocity measurement. You
can configure the scaling using the time basis and the number of increments that your
encoder delivers per unit.
Example:
Your SSI absolute encoder operates with a resolution of 12 bits per revolution and performs
4096 increments per revolution. The velocity should be measured in revolutions per minute.
In this case, you need to configure 4096 Increments per unit and a time basis of one minute.
Counting, measurement and position detection
Function Manual, 12/2017, A5E32009889-AG
The basics of counting, measurement and position detection
61