Acromag TT231-0600, User Manual, Page: 9 / 41

Model TT231-0600 Two-Wire RTD Transmitter w/USB
Acromag, Inc. Tel: 248-295-0880
- 9 - http://www.acromag.com
- 9 - http://www.acromag.com
Output/Power
Connections…
In most installations, the loop power supply will be local to either the transmitter,
or local to the remote receiver. Common receiver devices include the input channel
of a Programmable Logic Controller (PLC), a Distributed Control System (DCS), or a
panel meter. Some receivers already provide excitation for the transmitter loop
and these are referred to as “sourcing inputs”. Other receivers that do not provide
the excitation are referred to as “sinking” inputs, and these will require that a
separate power supply connect within the loop. These types of receivers are
depicted below:
WARNING: For compliance to applicable safety and performance standards,
the use of twisted pair output wiring is recommended. Failure to adhere to
sound wiring and grounding practices as instructed may compromise safety,
performance, and possibly damage the unit.
TIP - Ripple & Noise:
Power supply ripple at 60Hz/120Hz is normally reduced at the
load by the transmitter, but additional filtering at the load can reduce this ripple
further. For large 60Hz supply ripple, connect an external 1uF or larger capacitor
directly across the load to reduce excessive ripple. For sensitive applications with
high-speed acquisition at the load, high frequency noise may be reduced
significantly by placing a 0.1uF capacitor directly across the load, as close to the load
as possible.
TIP - Inductive Loads: If the two-wire current loop includes a highly inductive load
(such as an I/P current-to-pressure transducer), this may reduce output stability. In
this case, place a 0.1uF capacitor directly across the inductive load and this will
typically cure the problem.
INPUT SIDE OUTPUT SIDE
MODEL TT231-0600
MODEL TT231-0600 OUTPUT WIRING
OUTPUT
TERMINALS
+ -
COMMON
C C
TB3
TB4
TOP VIEW
(OUTPUT SIDE)
+
-
6
5
6 5
8 7
"SINKING OUTPUT" CONNECTIONS WITH
LOOP+
LOOP-
TB4
TB3
+
-
TWISTED PAIR
TERMINALS
I
I
POWER LOCAL TO THE RECEIVER
The 24V DC Excitation is
Provided by the Card
+
RCV
DCS/PLC SINKING
24VDC
Two-Wire Output Connections to the Input Card of a Distributed Control
System or Programmable Logic Controller.
+
-
24VDC POWER SUPPLY
I
I
COMMON TWO-WIRE TRANSMITTER CONNECTION TO "SOURCING" AND "SINKING" INPUT RECEIVERS
+
-
INPUT CARD
-
+
RCV
+
-
P
DCS/PLC SOURCING
24VDC
INPUT CARD
+
-
OR
SOURCING INPUT RECEIVER SINKING INPUT RECEIVER
The 24V DC Excitation is Provided
by a Separate Power Supply