Continuous Frequency Measurement; Table 2-10 Calculation Of The Update Time - Siemens SIMATIC ET 200S Operating Instructions Manual

1Count24V/100kHz
2.7 Measurement Modes
2.7.4

Continuous Frequency Measurement

Definition
In frequency measurement mode, the 1Count24V/100kHz counts the pulses that arrive
within a dynamic measuring time.
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 2-10 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.
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 2-24
Limit-Value Monitoring
The following value ranges are permitted for limit-value monitoring:
Encoder type
24-V encoders 0 to 99,999,999 Hz*10
62
Update 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
Low limit f
u
Range of n
n
min
1
(10 ms/T [ms]) +1
DP DP
1
DP
are omitted.
DP
High limit f
f +1 to 100,000,000 Hz*10
-3
u
Operating Instructions, 02/2007, A5E00124867-05
n
max
1000
1000
1
10000 ms/T
. The measured
-3
o
-3
Technological Functions
[ms]
1
DP