WAGO I/O System 750
Process Image 35
750-637 Incremental Encoder Interfaces
Manual
Version 1.6.1
Public
4
Process Image
Mapping of process data in the process image of fieldbus systems
The representation of the I/O modules’ process data 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 fieldbus coupler/controller used.
The I/O module provides the fieldbus coupler/controller with a 6-byte input and
output process image via 2 logical channels.
The set values to be set are stored in 4 output bytes (D0 … D3). The read-in
process data is stored in the 4 input bytes (D0 … D3). Two control bytes (C0, C1)
and two status bytes (S0, S1) control the data flow and are used to select the set
and actual values.
Table 25: Process Image
Process Image
Input
Output
S0
Status byte S0
C0
Control byte C0
D0
Process data byte 0 (LSB)
D0
Set value byte 0 (LSB)
D1
Process data byte 1
D1
Set value byte 1
S1
Status byte S1
C1
Control byte C1
D2
Process data byte 2
D2
Set value byte 2
D3
Process data byte 3 (MSB)
D3
Set value byte 3 (MSB)
Various process data is displayed as a function of bit 0 and bit 1 in control byte
C1 (see Table “MapPZD, All Versions, Except 750-637/000-004”):
• Counter value
• Latch value
• Rate
• Set value
The setting is mirrored in bit 0 and bit 1 of status byte S1.