KROHNE MFC 400 EN - Manual (Page 138)

9
DESCRIPTION OF HART INTERFACE
138
MFC 400
www.krohne.com 08/2013 - 4002075802 - MA MFC 400 R02 en
9.3.3 Multi-Drop connection (3-wire connection)
Connection of 2-wire and 4-wire devices in the same network. In order that the current output of
the signal converter is working continuously active, an additional third wire must be connected
to the devices in the same network. These devices must be powered via a 2-wire loop.
1 Primary Master
2 HART
® modem
3 HART ® signal
4 2-wire external devices (slaves) with 4…20 mA, addresses > 0, powered by current loop
5 Signal converter terminals A (C)
6 Signal converter terminals A- (C-)
7 Connection of active or passive 4-wire devices (slaves) with 4…20 mA, addresses > 0
8 Load ≥ 250 Ω (Ohm)
9 Secondary Master
10 Power supply
.book Page 138 Monday, August 26, 2013 9:05 AM