Process Image - WAGO I/O-SYSTEM 750 Manual

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Process Image

4 Process Image
The 753-454 I/O module provides 1 status byte (8 bits) and 1 data word (16 bits).
Whether the status byte is read out via the fieldbus depends on how diagnostic
information is transmitted by the respective fieldbus or fieldbus
couplers/controllers used. In any case, the status byte can be read out using the
WAGO-I/O-CHECK commissioning tool via the service port of the fieldbus
coupler/controller.
The digitalized measured value is transmitted to the process image of the fieldbus
coupler/controller in a data word (16 bits) as an 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 3 least
significant bits (B0 ... B2).
If the measurement is above the measuring range, bit B0 is set = 1, and if the
measurement is below the measuring range or if a wire breaks, bits B0 and B1 are
set = 1.
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.
For the I/O module 753-454 the input current ranging from 4 mA to 20 mA is
scaled on the numerical values ranging from 0x0000 bis 0x7FF8.
WAGO I/O-SYSTEM 750
753-454 2AI 4-20mA Diff.
Manual
Version 1.1.0