WAGO I/O SYSTEM 750 XTR
Process Image 33
750-481/040-000 2AI RTD Ex i XTR
Manual
Version 1.1.0
4
Process Image
Mapping of process data in the process image of fieldbus systems
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 from the section “I/O Modules” included in the description
concerning the process image of the corresponding coupler/controller.
Evaluation of Status Byte
Some fieldbus systems can process status information of process value by
means of a status byte.
This status byte can be displayed via the commissioning tool
WAGO-I/O-
CHECK
.
However, processing via the fieldbus coupler/controller is optional, which means
that accessing or parsing the status information depends on the fieldbus system.
The input module 750-481/040-000 transmits 16-bit measured values and 8
optional status bits per channel.
4.1
Configuration for Pt Resistance Sensors
To evaluate the platinum resistance sensors, the measured values of the
resistance are converted and sent as temperature values. All temperature values
are represented in a standard numeric format. The possible numerical range
matches the defined temperature range of the Pt
sensors from −200 °C to
+850 °C.
In the Pt 100, Pt 200, Pt 500 and Pt 1000 settings, the temperature values of the
sensors are represented with a resolution of 1 digit per 0.1 °C within a word
(16 bits). Thus, 0 °C corresponds to the numeric value 0x0000 and 100 °C to
0x03E8 (dec. 1000). Temperature values below 0 °C are represented in two’s
complement binary form.