Emerson Rosemount 644, Reference Manual

Page: 133 / 182

123
Reference Manual
00809-0200-4728, Rev RA
Appendix A: Specifications and Reference Data
April 2015
Specifications and Reference Data
Sensor connections
Tagging
Hardware

13 characters total

Tags are adhesive labels affixed to the side of the transmitter

Permanently attached to transmitter

Character height is 1 /
16
-in (1.6 mm)
Software

The transmitter can store up to 8 characters for the HART protocol

Order software tag with C1 option code
A.5.4 4–20 mA/HART specifications
Power supply
External power supply required. Transmitters operate on 12.0 to 42.4 Vdc transmitter terminal
voltage (with 250 ohm load, 18.1 Vdc power supply voltage is required). Transmitter power
terminals rated to 42.4 Vdc.
Load limitations
Note
HART communication requires a loop resistance between 250 and 1100 ohms. Do not
communicate with the transmitter when power is below 12 Vdc at the transmitter terminals.
Rosemount 644 Sensor connections diagram
* Rosemount Inc. provides 4-wire sensors for all single element RTDs.
You can use these RTDs in 3-wire configurations by leaving the
unneeded leads disconnected and insulated with electrical tape.
Maximum load = 40.8 X (supply voltage - 12.0)
(1)
(1) Without transient protection (optional).
2-wire
RTD and
3-wire RTD
and
4-wire RTD
and
T/C
and mV
*
1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
1240
1000
750
250
0
10
12.0 Min
18.1 30 42.4
Supply Voltage (Vdc)
HART and Analog
Operating Range
4–20 mA dc
Lo
ad
(
O
h
m
s)
500
1100
Analog Only
Operating Range