KROHNE MFC 300 EN - Manual (Page 151)

DESCRIPTION OF HART INTERFACE
9
151
MFC 300
www.krohne.com 02/2012 - 4000498602 - MA MFC 300 R03 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 151 Monday, February 6, 2012 11:01 AM