FM502-CMS Used as Time Frequency Meter

The function block CMS_IO_FREQ_SCAN is used to measure times, frequency and rotation speeds on channel Z+ of the Function Module CMS_IO_FREQ_SCAN: CMS_IO_FREQ_SCAN

Possible operation modes: 15-1 <no title>

The Function Module provides one channel (Z+) which can be used to measure times, frequencies and rotational speeds with a resolution of 1 µs.

Example of timing

Values measured according to configuration input parameters \ and example

EN_0	EN_1	EN_FREQ	Type	1	2	3	4
FALSE	FALSE	TRUE	No measurement	0	0	0	0
FALSE	TRUE	TRUE	Between 2 falling edges		500		450
TRUE	FALSE	TRUE	Between 2 rising edges			350
TRUE	TRUE	TRUE	Between any 2 edges	300	200	150	300
FALSE	FALSE	FALSE	No measurement	0	0	0	0
FALSE	TRUE	FALSE	Between the rising edge and the subsequent falling edge	300		150
TRUE	FALSE	FALSE	Between the falling edge and the subsequent rising edge		200		300
TRUE	TRUE	FALSE	Between any 2 edges (start between edge 0 and 1)  *)		200		300
TRUE	TRUE	FALSE	Between any 2 edges (start between edge 1 and 2)  *)			150

*) The timing measurement is a single shot process. The function block manages renew of the measurement as soon as the enable input is valid. Because of timing required to exchange management bits on the bus, it is not able to provide the time measurement between two adjacent edges. Therefore, the time measured depends when the measurement is started.

Depending on the input parameters of the function block, the result of the measurement can be read as time in µs, frequency in Hz or speed of rotation in rotation per minute.