Rockwell Automation 1771-QB Linear Pos. - Manual (Page 45)

Installing the Linear Positioning Module
Chapter 5
5Ć6
2. Open the module locking latch on the I/O chassis and insert the module
into the slot keyed for it.
3. Press firmly to seat the module into the backplane connector.
4. Secure the module with the module locking latch.
ATTENTION: Don’t force a module into the backplane connector.
If you can’t seat a module with firm pressure, check the alignment
and keying. Forcing a module can damage the backplane connector
and the module.
Through the module’s terminals, you connect the module to external devices.
The exact wire gauge and maximum allowable length depends upon the devices
being connected. Here are some general rules to follow when you connect the
terminals:
don’t use wire with too large a gauge. The maximum practical wire gauge is
14 AWG.
keep low level conductors separate from high level conductors. Follow the
practices outlined in Publication 1770-980 P2LC Grounding and Wiring
Guidelines.
keep your power supply cables as short as possible–less than 50 feet is
preferable.
Using Shielded Cables
For many connections, you are instructed to use shielded cables. Using shielded
cables and properly connecting their shields to ground protects against
electromagnetic noise interfering with the signals transmitted through the
cables. Connect each shield to ground at one and only one end. At the other end,
cut the shield foil and drain wire short and cover them with tape. This will
protect them against accidentally touching ground. Keep the length of leads
extending beyond the shield as short as possible.
Figure 5.4 shows shielded cable connections for one control loop. Mount a
ground bus directly below the I/O chassis to provide a connection point for the
cable shield drain wires and the common connections for the input and output
circuits. Connect the I/O chassis ground bus through 8 AWG wire to the central
ground bus to provide a continuous path to ground.
Wiring Guidelines