Continuous Period Measurement; Table 2-16 Calculation Of The Update Time - Siemens SIMATIC ET 200S Operating Instructions Manual

2.7.8

Continuous Period Measurement

Definition
In period measurement mode, the 1Count24V/100kHz indicates the dynamic measuring time
as a period. If the period is less than the update time, then an average is calculated for the
period.
Update Time
The 1Count24V/100kHz updates the measured values cyclically. You preset the update time
with the Update Time parameter (see table). You can change the update time during
operation.
Table 2-16 Calculation of the Update 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 1Count24V/100kHz generates a parameter assignment
error and will not go into isochrone mode.
Period Measurement
The value of the calculated period is given in the unit 1 µs and 1/16 µs. The measured period
can be read in the feedback interface (byte 0 to 3).
Figure 2-28
Technological Functions
Operating Instructions, 02/2007, A5E00124867-05
Update time
Any T n x 10 ms
DP
T < 10 ms n x T
DP
T ≥ 10 ms n x T
DP
Period Measurement with Gate Function
Range of n
n
min
1
10 ms/T [ms] +1
DP DP
1
DP
are omitted.
DP
1Count24V/100kHz
2.7 Measurement Modes
n
max
12000
12000
1
120000 ms/T [ms]
DP
1
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