750-404/000-003 [Frequency Counter 0.1 Hz-100 kHz] • 37
Process Image
WAGO-I/O-SYSTEM 750
I/O Modules
T
P
T
1
0xFFFFFFFF
0xFFFFFFFF
D0..D3
D0..D3
D0..D3
D0..D3
D0..D3
Input
frequency
Data valid
Process
data
T
P
= 1/f Current period
T
1
Maximum data hold time (parameterizable)
Input Data
D0..D3
Fig. 2.1.4-4: Timing diagram for process data update sequence
g040435e
(integration time = 1 period)
0xFFFFFFFF
4 T
P
T
1
0xFFFFFFFF
D0..D3
D0..D3
Input
frequency
Data valid
Process
data
T
P
= 1/f Current period
T
1
Maximum data hold time (parameterizable)
Input Data
D0..D3
Fig. 2.1.4-5: Timing diagram for process data update sequence
g040436e
(integration time = 1 period)
2.1.4.7 Process Image
Using the I/O module 750-404/000-003, a 5 byte input and output process
image can be transferred to the fieldbus coupler / controller via two logical
channels.
The two output bytes (D0, D1) contain the setting Watchdog time in binary
format. The other output bytes (D2, D3) are not used. The four input bytes
(D0 ... D3) contain the frequency value in binary format. The control byte C0
serves for setting the integration time, the Watchdog time, the representation
of the measured frequency value and the outputs. The status byte S0 displays
the acknowledgement of the settings and shows the status of the inputs and
outputs.
Attention
The representation of the process data of some I/O modules or their
variations in the process image depends on the fieldbus coupler/-controller
used. Please take this information as well as the particular design of the
respective control/status bytes from the section "Fieldbus Specific Design of
the Process Data" included in the description concerning the process image
of the corresponding coupler/controller.
