Process Image; Overview - WAGO 750-486 Manual

WAGO-I/O-SYSTEM 750
750-486 4AI 0/4-20 mA, Ex i
4

Process Image

The 750-486 I/O module provides 1 status byte (8 bits) and 1 data word (16 bits)
per channel.
The I/O module supplies the input current range 0 ... 20 mA or 4 ... 20 mA or
3.6 ... 21 mA (sensor type NAMUR NE43) at a resolution of 13 bits.
The digitalized measured value is transmitted to the process image of the
coupler/controller in a data word (16 bits) as input byte "0" (low) and input byte
"1" (high). This value is mapped with a resolution of 12 bits on bit B3 ... B14.
Status information, which can be evaluated for fault detection, is contained in the
two least significant bits (B0 ... B1).
In the case of a measurement underrange or overrange, bits B0 and B1 are
set = 1.
Bit 2 is not defined and is not evaluated.
The WAGO-I/O-CHECK commissioning tool can be used to configure the
required operating mode. The I/O module can also be parameterized via
PROFIBUS and PROFINET device description (GSD file).
The parameterization description can be found in the appendix in Section
"Configuration and Parameterization via GSD File with PROFIBUS DP and
PROFINET IO."
4.1

Overview

Presentation of control/status bytes a function of fieldbus
coupler/controller!
The I/O module always makes its complete process image incl. control/status
bytes available to the fieldbus coupler/controller. The WAGO-I/O-CHECK
commissioning tool accesses the complete commissioning process image. The
fieldbus coupler/controller uses a different process image to stage cyclic process
data via the fieldbus. In the other process image, depending on the fieldbus
coupler/controller, the representation of control/status bytes can be suppressed.
Process Image 33
Manual
Version 1.1.2