Emerson Rosemount 5400 Series - Page 16

June 2016
16
Quick Start Guide
Load limitations
For HART communication, a minimum load resistance of 250  is required.
For maximum load resistance, see Figure 4.
Figure 4. Maximum Loop Resistance
Intrinsically safe installations
Non-hazardous and Non-sparking/energy limited installations
Explosion-proof/flameproof (Ex d) installations
Note
For the Ex d case, the diagram is only valid if the HART load resistance is at the + side and if the
- side is grounded, otherwise the load resistance value is limited to 435 .
10 20
16
30
200
400
600
800
1000
1200
1400
40 50
24
586
847
U
E
(V)
Operating region
R(
10 20
16
30
200
400
600
800
1000
1200
1400
40 50
42.424
586
1387
U
E
(V)
R(
Operating region
10 20 30
200
400
600
800
1000
1200
1400
40 50
24 42.4
1148
348
U
E
(V)
R(
R(): Maximum Load Resistance
U
E
(V): External Power Supply Voltage
Operating region