This guide describes how to replace the MOC cable that connects from the MOC module of the safety PLC to the motor encoders. The is the cable labeled CAB-036.

You will need to lift up the plate with the safety PLC mounted to it. This can be easier and safer to do with a second person to help hold it.

Things you'll need

• A new MOC cabel harness (CAB-036) from MiR

• A pair of pliers or scissors to cut cable ties

• Cable ties

• T30 and T10 screwdrivers

• A 15 Nm torque wrench with a T45 head

Before replacing the cable

Step 1: Turn off the robot and disconnect the battery. To disconnect the battery, follow these steps:

1. Remove the rear cover by pressing the two white buttons and pulling off the cover. When removing the cover, un-click the two bottom corners first and then the two top corners.
   
2. Turn the Battery lock switch clockwise to release the Battery lever.
   
3. Pull the Battery lever down to disconnect the battery.
   
4. Turn the Battery lock switch counter-clockwise to lock the battery lever again.

Step 2: Remove the front cover by unscrewing the two screws with a T30 screwdriver and pulling off the cover. When removing the cover, un-click the two bottom corners first and then the two top corners.

Step 3: Disconnect the antennas. Unscrew the antennas from the top compartment covers and remove them.

Step 4: Disconnect the antenna cables from the top cover. Unscrew the two nuts from the antenna connectors using a 10 mm wrench, and push the antenna connectors through the covers.

Step 5: Remove the top compartment covers from the top plate by unscrewing the eight screws with a T10 screwdriver. Make sure the antenna cables are not connected to the compartment covers.

Step 7: Pull out the battery. Be sure to lift the battery over the rear status light, and then pull it out gently.

Step 8: Unscrew the two screws on the battery plate. This will enable you to remove the plate where the safety PLC is mounted.

Step 9: Remove the plate beneath the battery that the safety PLC is mounted to. To remove the plate, lift the plate approximately 3 cm, and then pull it 5 cm towards the rear end of the robot. You should then be able to tilt the plate upwards and place it at the rear end of the robot.

Removing the cable

Step 1: In the front compartment, disconnect the two motor encoder cable connectors from the MOC cable connectors. The MOC cables are the two turquoise colored cables connected to circular connectors.

Step 2: Gently, pull the two MOC cables from the front compartment into the center compartment.

Step 3: Disconnect the D-sub connector from the MOC module on the safety PLC. This is the other end of the cable.

Step 4: Cut any cable ties keeping the MOC cable tied to any other cables.

Step 5: Gently remove the cable from the robot.

Replacing the cable

Step 1: Place the new cable into the center compartment, and feed the ends with the two connectors through to the front compartment.

Step 2: Connect the two connectors to the appropriate motor encoder cables. The teal cables from the center compartment are labeled Left and Right. The cable labeled Right must be connected to the encoder cable coming from the right side of the robot and vice-versa for the cable labeled Left. Under Testing you will run a test to check if you have connected the connectors correctly. Provided you run the test to verify that the cables are connected correctly, you will not damage the robot if you accidentally swap the cables.

Step 3: Use cable ties to group the MOC cable together with the other cables as they were before.

Step 4: Connect the D-sub MOC connector to the MOC module on the safety PLC.

Step 5: Reassemble the robot by following the steps in Before replacing the cable in reverse.

Testing

The cable connecting the encoders to the MOC module provide the speed data the robot uses to change to the correct Protective field. To test if this is working correctly, follow these steps: 

1. Turn on the robot and wait for it to start up. If the robot reports any encoder related errors, it is possible that the circular connectors or the D-sub connector may not be securely connected. Check that the circular connectors are locked and the D-sub connector is properly connected.

2. Approximately two meters in front of the robot, place a foam block or another piece of material that is at least 30 cm tall and will not damage the robot if it collides with it at full speed.

3. Put the robot into Manual mode, and drive the robot toward the block at full speed.

If the robot stops before hitting the block, you have successfully replaced the MOC cable.

If the robot drives into the block before stopping, the encoder cables have been swapped. Open the front compartment and swap the encoder and MOC cable connections.