Figure 24 - Single Connection And Multidrop Hart Setups - FCI MT100 Installation, Operation And Maintenance Manual

MT100 Multipoint Flow Meter
I/O Connections
As shown in Figure 23 the SB4 main board provides an input/output signal interface for connection to various peripheral interfaces. For
these interfaces, route the cable/wires through a conduit opening at the enclosure bottom and connect to the appropriate
connector/terminals.
HART
Connect the installation HART wiring to the appropriate J9 Phoenix connector terminals depending on the application. The connector
accepts 28-16 AWG (0.14 mm
● Single Connection – The instrument supplies power to the loop and controls the current as well. For this application connect HART+
to J9-1 (INT+) and HART- to J9-2 (INT-).
● Network (Multidrop) Connection – The instrument receives loop power from the network, and controls the current. For this
application connect external HART+ to J9-2 (EXT+) and external HART- to J9-4 (RTN).
The block diagram in
diagram below only if the external HART interface/wiring does not have this resistance built-in (HART requires a minimum loop resistance of 230 Ω).
C R
ABLING ECOMMENDATION
Use a shielded, twisted-pair instrument grade wire (min. 24 AWG for runs less than 5000 ft/1500 m; min. 20 AWG for longer distances). The RC
value of the wire (Total Resistance x Total Capacitance) must be less than 65 µs (not a concern for point-to-point topology with a run less than
328 ft/100 m). A cable designed for HART/RS-485 such as Belden 3105A is recommended for complex setups and/or particularly long runs.
Note:
Internal Loop Power
+
J9-1
MT100
HART
–
J9-2
J9-1
J9-2
MT100
HART
J9-4
Fluid Components International LLC
-1.5 mm ) wire (refer to
2 2
Figure 24 below shows the single connection and multidrop HART setups. Use a 250 Ω 1%, ≥ 0.3 W resistor as shown in the
The HART communications digital signals are superimposed on top of the channel #1 current loop (4-20 mA) output.
When HART communications is in use, the HART current loop channel #1 MUST be configured as FLOW to comply
with the HART protocol. The channel #1 current loop output is configured as FLOW by default at the factory.
HART
I/O
HART
R
Master
LOAD
J9-1
J9-2
MT100
HART
J9-4
Figure 24 – Single Connection and Multidrop HART Setups
Table 2, page 23 for wire size vs. length info).
External Loop Power
J9-1 NC
MT100
HART
+
J9-2
–
J9-4
(a) HART Single Connection
J9-1
J9-2
MT100
HART
J9-4
(b) HART Network, Multidrop
INSTALLATION
Network P.S.
24 VDC
HART
HART– HART+
I/O
R
LOAD
Network P.S.
24 VDC
HART
HART– HART+
I/O
HART
R
Master
LOAD
J9-1
J9-2
MT100
HART
J9-4
HART
Master
C01364-1-1
27