Model DT23x-0600
Dual Two-Wire DC I/V Input Transmitters
Acromag, Inc. Tel: 248-295-0880
- 9 -
http://www.acromag.com
- 9 -
https://www.acromag.com
Output/Power Connections
NOTE:
Because this unit’s
microcontroller is powered from
output 1, you must connect power
to output loop 1 to operate this
unit in any mode (single
transmitter, dual transmitter, and
signal splitter). Output loop 2 only
powers input 2 and is not used in
single channel 1 transmitter mode.
This dual channel transmitter has two isolated ANSI/ISA Type 2 outputs in which the
channel
’s power and output signal share the same two leads
or current loop, and
each transmitter
output has a “floating” connection with respect to earth ground.
Connect a DC power supply and load in series in each of the two-wire output loops
as shown in the drawings that follow.
•
Passive output connections are not polarized
. The and
–
designations
are for reference only with current normally input to and returned via
Output- (current sinking). Output loop 1 powers input 1 & the microcontroller.
•
Loop supply voltages should be from 7-32V DC
with the 7V minimum
transmitter voltage level adjusted upward to drive nominal current to the loop
load (up to 24mA*R
load
), plus any transmission line drop.
•
Variation in power supply voltage has negligible effect on transmitter
accuracy
between the 7V minimum required by the transmitter and 32V
maximum allowed (may drive loads up to 32-
7/0.024=1041Ω at 24mA)
.
•
Variation in load resistance has negligible effect on output accuracy
if the loop
supply voltage level is set correctly for the load resistance (see above).
•
Note the traditional placement of earth ground in a two-wire current loop.
The transmitter output is not earth grounded at the transmitter. Output Earth
ground is normally applied at the loop power supply minus terminal. The two-
wire transmitter output varies off earth ground by the voltage drop in the load
resistance and lead-wire of the loop.