66
9900 Transmitter
Multi-Drop Mode
Up to four 9900 Transmitters can be connected in Multi-Drop mode using the H COMM Module.
To ensure proper operation in Multi-Drop mode, con
fi
gure each 9900 Transmitter with its own poll address using a
con
fi
guration tool (laptop or hand-held device).
After con
fi
guring the 9900 Transmitter for multi-drop function, reset the Transmitter (remove power for
fi
ve seconds
then apply power) before use.
–
+
9900
Connections
Loop +
Loop –
PLC
Device
(HART Master)
Hand-held device
(Secondary HART Master)
Loop +
Loop –
Loop +
Loop –
Loop +
Loop –
Device 1
Device 2
Device 3
Device 4
Red
Black
Red
Black
Red
Black
Red
Black
Red
Black
Connecting HART in Multi-Drop mode
(Typical four-unit installation)
NOTE:
On pages 64-69, the term “9900 Transmitter” or “Transmitter” will assume the H COMM Module is installed
unless otherwise noted.
H COMM Module Wiring