Frequency Measurement - Siemens SIMATIC ET 200S Operating Instructions Manual

3.7.3

Frequency Measurement

Definition
In frequency measurement mode, the 1Count5V/500kHz counts the pulses that arrive within
a set integration time.
Integration time
You preset the integration time with the Integration Time parameter (see table).
Table 3-10 Calculation of the Integration Time
Boundary conditions
Non-isochrone mode
Isochrone mode
Any digits after the decimal point that come about after dividing by T
1
These limits must not be violated. If these limits are violated, the 1Count5V/500kHz generates a parameter assignment
error and will not go into isochrone mode.
Frequency Measurement
The value of the calculated frequency is made available in the unit Hz*10
frequency value can be read in the feedback interface (byte 0 to 3).
Figure 3-24
Technological Functions
Operating Instructions, 02/2007, A5E00124867-05
Integration time
Any T n x 10 ms
DP
T < 10 ms n x T
DP
T ≥ 10 ms n x T
DP
Frequency Measurement with Gate Function
Range of n
n
min
1
(10 ms/T [ms]) +1
DP DP
1
DP
are omitted.
DP
1Count5V/500kHz
3.7 Measurement Modes
n
max
1000
1000
1
1000 ms/T [ms]
DP
. The measured
-3
1
167