MiniPuck Model ST132-06x0 Two-Wire TC/mV Transmitter
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Acromag, Inc. Tel:248-295-0880 Fax:248-624-9234 Email:
7
Here are example transmitter connection diagrams for “sourcing” and
“sinking” receiver types:
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 the 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 by placing a 0.1uF capacitor directly
across the load.
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.
The unit housing is plastic and does not require an earth ground connection.
If the transmitter is mounted in a metal housing, a ground wire connection is
typically required, and you should c
onnect the metal enclosure’s ground
terminal (green screw) to earth ground using suitable wire per applicable
codes. See the Electrical Connections Drawing for Output/Power and note
the traditional position of earth ground for the two-wire output current loop.
The Type II transmitter output terminals have a floating connection relative
to earth ground. Earth ground is normally applied at the output loop power
minus terminal and in common with the loop load or loop receiver minus.
•
Do not earth ground any input lead and use only insulated/non-
grounded TC sensors. This transmitter does not isolate its input signal.
•
Respect the traditional position of earth ground in a two-wire current
loop and avoid inadvertent connections to earth ground at other points,
which would drive ground loops and negatively affect operation. This
includes the USB connection to the transmitter, which should be made
via a USB isolator, as most Personal Computers earth ground their USB
ports, and this makes contact with both the signal and shield grounds.
ELECTRICAL
CONNECTIONS
Output/Power
Connections
Earth Ground
Connections
TRX
+
R
C
V
+
-
P
DCS/PLC SOURCING
24VDC
Connecting the ST132 Two-Wire Transmitter to
a "SOURCING" Input Card of a Digital Control
System or Programmable Logic Controller (e.g.
24V DC Excitation is Provided by Card)
I
+
R
C
V
DCS/PLC SINKING
24VDC
Connecting the ST132 Two-Wire Transmitter to
a "SINKING" Input Card of a Digital Control
System or Programmable Logic Controller with
24V DC Excitation Provided by Separate Power
Supply.
+
-
24VDC POWER SUPPLY
I
I
COMMON TWO-WIRE TRANSMITTER CONNECTION TO "SOURCING" AND "SINKING" INPUT RECEIVERS
+
-
+
Twisted Pair
Twisted Pair
INPUT CARD
INPUT CARD
-
6
5
TRX
I
+
6
5