WIKA TIF52 - Handbuch (Seite 22)

22 WIKA operating instructions models TIF50, TIF52
GB
14009686.02 03/2012 GB/D
7.3 HART ® signal
The HART ® signal is measured directly via the 4 ... 20 mA signal line. The measuring circuit
must have a load of at least 250 Ω. However, the load must not be too high, as otherwise,
in the case of relatively high currents, the terminal voltage at the transmitter will be too low.
For that reason, connect the cable clamps of the modem and/or the HART ® communicator,
as described (see chapter 6.4 "HART ® configuration tree") or use the existing communica-
tion connectors of a power supply/line transformer. The connection of the HART ® modem
and/or the HART ® communicator is not dependant on polarity! The HART ® modem or the
HART ® communicator may also be connected parallel to the resistor! When connecting
an Ex-version of the transmitter, observe the special conditions for safe use (see chapter 9
"Notes for mounting and operating in hazardous areas").
User interface
7. Electrical connection
The connected wires must be checked to ensure they are connected properly. Only
well-secured wires can guarantee a fault-free operation.
Status data
Operating keys
Unit line, info line
Bar graph
Measured value