YOKOGAWA DPharp EJX***A Series - 2.5 Interconnection Between DPharp and the HART Configuration Tool

<2. Connection>
2-4
IM 01C25T01-06EN
2.5 Interconnection Between
DPharp and the HART
CongurationTool
The HART conguration tool can interface with the
transmitter from the control room, the transmitter
site, or any other wiring termination point in the
loop. To communicate, the tool must be connected
to the signal line in parallel with the transmitter; the
connections are non-polarized. The HART digital
signal is superimposed on the analog signal. Figure
2.2 illustrates the wiring connections for direct
interface at the transmitter site for the DPharp. The
HART conguration tool can be used for remote
access from any terminal strip as well.
USB
FieldMate
Modem
Relaying
terminals
Distributor
Control room
Terminal
board
USB
PC/FieldMate
HART configuration tool
DPharp
F0202.ai
USB
FieldMate
Modem
Relaying
terminals
Power
Supply
Control room
Terminal
board
USB
PC/FieldMate
HART configuration tool
DPharp
Receiver
 4 to 20 mA output
 1 to 5 V output (3-wire)
Figure2.2 ConnectingtheHARTConguration
Tool
2.6 Power Supply Voltage and
Load Resistance
4-20mA
When conguring the loop, make sure that the
external load resistance is within the range in the
gure below.
(Note) With an intrinsically safe transmitter, external load
resistance includes safety barrier resistance.
600
250
0 10.5 16.6 25.2
42
External
load
resistance
R (Ω)
Power supply voltage E (V DC)
F0203.ai
Communication
applicable range
R=
E–10.5
0.0244
Figure2.3 RelationshipbetweenPowerSupply
Voltage and External Load Resistance