WAGO 750-404 Manual page 39

RANGE_
Attention
When a new frequency range is requested, the application has to wait for
valid data until the RANGE_SEL ACK bits contain the new frequency
range.
The maximum delay can be calculated using the following formula:
If the gate is enabled the input data contains the last valid frequency value. In
this state the application cannot request a new range.
Attention
If the maximum possible frequency of the different ranges is raised (see the
table with maximum frequency ratings), the module will return the non valid
data 0xFFFFFFFF
Set Watchdog time:
To recognize static CLOCK signals, a watchdog timer is implemented. The
standard value for the timer is 10s. The timer resets on every Power On.
The application is able to change the watchdog time during operation by using
the CONTROL byte.
This can be initiated by writing the corresponding value into the output bytes
D 1 and D 0 before setting the T
The success of the parameter transfer is acknowledged by the module via the
T
VD
WAGO-I/O-SYSTEM 750
I/O Modules
750-404/000-003 [Frequency Counter 0.1 Hz-100 kHz]
RANGE_
SEL1 SEL0
Integration over ...
0 0 1 period
0 1 4 periods
1 0 16 periods
1 1 16 periods
T = 2 •
Dmax
.
H
ACK bit in the STATUS information.
Measuring
Maximum
method
frequency range
0.1 Hz ... 8 kHz
0.25 Hz ... 32 kHz
1 Hz ... 100 kHz
1 Hz ... 100 kHz
number of periods to be integrated
actual frequency
REQ bit in the CONTROL byte.
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• 39
Process Image
Measured –
value display
Frequency in 1/1000 Hz
Frequency in 1/100 Hz
Frequency in 1/10 Hz
Frequency in Hz