Table of Contents
Advertisement
48 •
750-671 [Steppercontroller]
Process Image
2.1.2.7
Process Image
The 750-671 I/O module provides the fieldbus coupler/controller 12 bytes
input and output process image via 1 logical channel. The data to be sent and
received are stored in up to 7 output bytes (D0 ... D6) and 7 input bytes (D0
... D6), depending on the operating mode. Output byte D1 and input byte D1
are reserved and have no function assigned. 1 I/O module control and status
byte (C0, S0) and 3 application control and status bytes (C1 ... C3, S1 ... S3)
provide the control of the data flow.
Please note
Mapping the process data of some I/O modules or their variations into the
process image is specific for the fieldbus coupler/controller used. You will
find both this information and the specific configuration of the relevant
control/status bytes in the section on "Fieldbus Specific Configuration of
Process Data" which describes the process image of the particular
coupler/controller.
2.1.2.7.1
Overview
A basic distinction is drawn between the cyclic process image and the mailbox
process image.
Off-
set
10
11
Switching between the two process images is conducted through bit 5 in the
control byte (C0 (C0.5). Activation of the mailbox is acknowledged by bit 5 of
the status byte S0 (S0.5).
Cyclic process image
(Mailbox deactivated)
Input Data
0
Status byte S0
1
Reserved
2
3
4
Process data
5
D0 ... D6
6
7
8
9
Status byte S3
Status byte S2
Status byte S1
Output Data
Output Data
Control byte C0
Status byte S0
Reserved
Process data
MB0 ... MB5
D0 ... D6
Control byte C3
Status byte S3
Control byte C2
Status byte S2
Control byte C1
Status byte S1
Mailbox process image
(Mailbox activated)
Input Data
Control byte C0
Reserved
Reserved
Mailbox
Mailbox
MB0 ... MB5
Reserved
Reserved
Control byte C3
Control byte C2
Control byte C1
WAGO-I/O-SYSTEM 750
I/O Modules
Advertisement
Table of Contents
