WIKA Pascal 100 - Manual (Page 20)

6 Commissioning, operation
20 WIKA Operating Instruction, Pascal 100 and Pascal 100/IS
GB
6.1.2.4 HART module
The HART module allows communication with HART instruments (usually transmitters) permitting
to acquire digital measurements, instrument data and modifying 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 allow the 24V to supply directly the output loop for the transmitter.
Further, it can supply a 250Ω load resistance electronically switchable necessary to HART
communication, permitting to avoid the use of an external one.
The following figure shows the pin connections in HART module:
Figure 3 – HART module
6.1.2.4.1 HART wiring
Depending by several factors and combination that the user can found in a plant, there are many
wiring possibility depending by:

Using module internal or external Power Supply.

Using internal or external load resistance.

Simultaneous analog connection of AO TRX to one Input module for mA reading
Please consider, if the user enable the internal load resistance, this will be connected between the
+HART and COM terminals.
Here same examples:
Figure 4 - Case 1: 24V from m odule, 250Ω from module
Transmitter
HART slave