Emerson Rosemount 1408A Reference Manual page 68

Specifications and reference data
May 2021
A.2.3 Digital output
Switching signal for high and low limits (using the same pin)
Output type
PNP/NPN configurable
Switching function
Normally open
Permanent current rating
< 50 mA
Maximum voltage drop
2.5 V
A.2.4 4-20 mA analog output
Load limitations
Maximum loop resistance is determined by the voltage level of the external power supply:
Maximum Loop Resistance = 43.5 × (External Power Supply Voltage - 18) + 600 Ω
Figure A-2: Load Limits
1200
1100
1000
A
900
800
700
600
A. Loop Resistance (Ω)
B. External Power Supply Voltage (Vdc)
68
1121
860
18 19 20 21 22 23 24 25 26
B
27 28 29 30
Rosemount 1408A Level and Flow Transmitter
Reference Manual
00809-0200-4480