Rockwell Automation Publication 1769-IN028C-EN-P - August 2016 11
Compact I/O Expansion Power Supplies
Follow these steps to assemble the Compact I/O system.
1. Disconnect your line power.
The power supply does not support removal or insertion of modules under power.
2. Check that the bus lever of the power supply to be installed is in the unlocked (fully
right) position.
3. Use the upper and lower tongue-and-groove slots to secure the power supply to an I/O
module.
4. Move the power supply back along the tongue-and-groove slots until the bus connectors
align with each other.
5. Push the bus lever back slightly to clear the positioning tab.
Use your fingers or a small screwdriver.
6. To allow communication between the controller and the I/O, move the bus lever of the
power supply and its adjacent I/O modules fully to the left until it clicks.
Make sure it is locked firmly in place.
7. Attach an end cap terminator to the last I/O module in the system by using the tongue-
and-groove slots as before.
8. Lock the end cap bus terminator.
WARNING: If you connect or disconnect wiring while the field-side power is on, an electrical arc
can occur. This could cause an explosion in hazardous location installations. Be sure that power is
removed or the area is nonhazardous before proceeding.
ATTENTION: When attaching expansion I/O power supplies, it is very important that the bus
connectors are securely locked together to ensure proper electrical connection.
IMPORTANT A 1769-ECR or 1769-ECL right or left end cap (respectively) must be used to terminate the
end of the serial communication bus.