Model TT235-0600
RTD/Resistance Thermometer Transmitter w/USB
Acromag, Inc. Tel: 248-295-0880
- 10 -
http://www.acromag.com
[
10
]
https://www.acromag.com
Output/Power
Connections
Connect a DC power supply and load in series in the two-wire loop as shown in the
drawing below. This transmitter has an ANSI/ISA Type II output in which the
transmitter
’s power and output signal share the same two leads, and the
transmitter output has a “floating” connection with respect to earth ground applied
at the loop supply minus terminal.
Output connections are not polarized. The and
–
designation are for
reference only with current normally input to and returned via
Output
–
(current-sinking).
Loop supply voltage should be from 12
–
32VDC with the minimum voltage level
adjusted to supply over-range current to the load, plus 11V MIN across the
transmitter, plus any transmission line drop.
Variations in power supply voltage between the minimum required and a
maximum of 32VDC across transmitter, has negligible effect on transmitter
accuracy.
Variation in load resistance has negligible effect on output accuracy, as long as
the loop supply voltage is set accordingly.
Note the traditional placement of earth ground in the current loop. The
transmitter output minus varies off this ground by the voltage drop in the load
resistance and lead-wire.
The traditional loop-
powered “sinking” output
connections are shown above.
Shielded twisted-pair wiring is often used at the output to connect the longest
distance between the field transmitter and the remote receiver as shown. The
output of this transmitter fluctuates relative to earth ground by the voltage drop in
the load and connection wire. This makes it flexible in the way it connects to various
“Receiver” devices.
ANY MODEL TT2XX-0600
I
I
I
R
LOAD
THIS TRANSMITTER IS CURRENT LOOP POWERED
NOTE: OUTPUT TERMINALS ARE NOT POLARIZED AND
PLUS & MINUS LABELS ARE FOR REFERENCE ONLY.
OPTIONAL WIRING TERMINALS C ARE HELD IN
COMMON AND USED FOR "SOURCING" LOOP WIRING.
SEE OPTIONAL OUTPUT WIRING DIAGRAM.
5
6
–
+
6
5
8
7
C
C
INPUT SIDE
OUTPUT SIDE
TOP VIEW
(OUTPUT SIDE)
TB3
(OUTPUT)
TB1
(INPUT)
TB2
(INPUT)
TB4
(COMMON)
TRADITIONAL LOOP-POWERED "SINKING OUTPUT" CONNECTIONS
MODEL TT2XX-0600 OUTPUT/POWER WIRING
DC SUPPLY
(12
–
32V)
EARTH
GROUND
SHIELDED
TWISTED PAIR
4
–
20mA
