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WAGO-I/O-SYSTEM 750
750-633 Up/Down Counter Ex i
Manual
Version 1.3.0 HW-Version 03, SW-Version 01
4.2.1
Set Measuring Method, Frequency Range and Measured
Value Display
The RANGE_SEL REQ bits in the control byte are used to set the measurement
methods and display of the frequency value. The maximum frequency value also
changes depending on the measuring method set. The following table shows the
different operating modes.
Table 25: Measuring Method, Frequency Range and Measured Value Display Settings
Measuring
Range
RANGE_
SEL REQ0
RANGE_
SEL REQ1
Measuring
Method
Maximum
Frequency Range
Measured
Value Display
Integration via
1
0
0
4 periods
20 Hz … 16 kHz
Frequency in
1/1000 Hz
2
0
1
4 periods
160 Hz … 20 kHz Frequency in
1/100 Hz
3
1
0
16 periods
4 kHz … 50 kHz
Frequency in
1/10 Hz
4
1
1
64 periods
16 kHz … 50 kHz Frequency in
Hz
Note the delay time when changing the frequency range!
When setting a new frequency range, there is a delay time until valid data are
read. After acknowledging the new frequency range settings via the
RANGE_SEL ACK bits, this delay time must be taken into consideration.
The following formula can be used to calculate the maximum delay time:
T
Dmax
= 2 x number of periods that are integrated / current frequency value
No range requirement for enabled gate!
If the gate is enabled, the input data receives the last valid frequency value. No
new range can be requested in this status.
Display of invalid frequency ranges
If the maximum frequency range is exceeded, the module returns the invalid value
0xFFFFFFFF.
4.2.2
Set Watchdog Time
To detect static CLOCK signals, a Watchdog time has been implemented. The
default value for the time is 10 s. The time is reinitialized at each power-on.
The application can change the Watchdog time during operation via the control
byte.
