Endress+Hauser mypro CLD 431, Руководство по эксплуатации

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Resistance
The required minimum supply voltage of the
transmitter depends on the resistance of the
evaluation instrument connected.
The following diagram shows the required
supply voltage when connecting the HART
interface and the maximum admissible
resistance in the transmitter circuit.
The maximum admissible resistance R
max
is
derived from the following formula:
with U
V
= supply voltage of the
transmitter circuit (DC)
U
M
= terminal voltage of the
transmitter (12 V DC)
I
max
= maximum current of the
transmitter (22 mA)
R
U U
V M
ax
max
m
I
=
−
30
U [V DC]
V
U [V DC]
V
20
17,5 12
10
100
200
820
750
250
300
400
500
600
700
800
900
R [ ]
Ω
R [ ]
Ω
supply voltage
resistance with
HART interface
re
sistanc
e
maximum
admissible
resistance
BUERDE.CDR
Fig. 3.19
Admissible resistance in
the transmitter circuit
Installation mypro CLM 431 / CLD 431 conductive
18 Hauser