Pressure Module; Hart ® Module - WIKA Pascal ET Betriebsanleitung

6. Commissioning, operation

6.1.3.3 Pressure module

The pressure module is installed only at factory location in accordance with the Pascal ET configuration required. It is possible
to install one pressure modules, able to support up to two sensors (2 internal, 2 external or a combination of both). Sensors
selection with range and their resolutions are in the table, see chapter 3.3 "Pressure sensors".
®
6.1.3.4 HART module
®
The HART module allows communication with HART
measurements and instrument data, and to modify settings. It can be inserted in the front panel in place of OUT A or OUT B
module.
It is a fully galvanically isolated board (like IN and OUT modules) from internal electronics of the Pascal.
The module allows the DC 24 V to directly supply the output loop for the transmitter.
Further, it can supply a 250 Ω load resistance electronically switchable necessary to HART
avoid the use of an external one.
The following figure shows the pin connections in HART
®
HART wiring
Depending on several factors and combination that the user can find in a plant, there are many wiring possibilities depending
on:
Using module internal or external power supply.
■
Using internal or external load resistance.
■
Simultaneous analogue connection of AO TRX to one input module for mA reading
■
Please consider, if the user enables the internal load resistance, this will be connected between the +HART and COM
terminals.
Here are some examples:
COM
WIKA operating instructions, model Pascal ET
®
instruments (usually transmitters) permitting to acquire digital
®
module:
COM
Fig. 3 - HART
+HART
24V
Fig. 4 - Case 1: DC 24 V from module, 250 Ω from module
®
communication, permitting to
+HART
24V
®
module
Transmitter
HART
®
slave
21
EN