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The Optimus™ control module inputs provide the required 250Ω impedance required for
HART communications. Optimus™ has been designed to handle up to 80mA combined
input current.
All of the input channel te
rminals are connected in parallel in the Optimus™ control
module. The location of a PRI150 radiation detector within the system is determined by
the configuration settings stored in the Optimus™ control module. The configuration maps
the unique HART address of each PRI150 radiation detector to the assigned channel. The
terminal numbering is provided for convenience in case the need for troubleshooting
arises.
4.2.3.2
Optimus™ HART 7 4
-20mA Output
Optimus™ presents the level output as a passive 4
-20mA current loop with HART 7
communications available over the current loop. The 4-20mA current output must be
connected to an active input on the plant DCS (for example, the DCS powers the current
loop).
In order to utilise HART 7 communications
the appropriate impedance (250Ω) must be
present in the loop.
Additional terminals are made available on the front of the Optimus™ control module to
connect a HART modem (orange connector). This is to allow communications with the
Optimus™ control module
for calibrating and monitoring purposes. This signal is digital
only and does not provide a 4-20mA signal. For these terminals to operate correctly, the
4-
20mA output should be correctly powered with the correct impedance (250Ω).
Figure 10. Local display.
