MicroLogix 1200 RTD/Resistance Input Module
7
Publication 1762-IN014B-EN-P - July 2013
Field Wiring Connections
Grounding the Module
This product is intended to be mounted to a well-grounded mounting surface such as a metal
panel. Additional grounding connections from the module’s mounting tabs or DIN rail (if used)
are not required unless the mounting surface cannot be grounded. Refer to Industrial
Automation Wiring and Grounding Guidelines, Allen-Bradley publication
1770-4.1
, for
additional information.
System Wiring Guidelines
Consider the following when wiring your system:
•
Do not use the module’s NC terminals as connection points.
•
Use Belden shielded, twisted-pair wire to ensure proper operation and high immunity to
electrical noise. See
“RTD Wiring Considerations”
.
•
To limit noise, locate RTD and resistance device signal wires as far away as possible from
power lines, load lines, and other sources of electrical noise, such as hard-contact
switches, relays, and AC motor drives.
•
Locate RTD modules away from other modules which generate a significant amount of
heat.
•
Under normal conditions, the drain wire and shield junction should be connected to
earth ground, via a panel or DIN rail mounting screw at the 1762-IR4 module end.
•
Keep shield connection to ground as short as possible.
•
To ensure optimum accuracy, limit overall cable impedance by keeping your cable as
short as possible. Locate the I/O system as close to your sensors or actuators as your
application will permit. See the table on the following page.
Terminal Block Layout
EXC 2
SENSE 2
RTN 2
EXC 3
SENSE 3
RTN 3
EXC 0
SENSE 0
RTN 0
EXC 1
SENSE 1
RTN 1
NC
NC
NC
NC
NC
NC
NC terminals are not intended for
use as connection points.
Do not connect any wires to the NC
terminals.
