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Safety System

The RoboSwap system utilizes a safety system comprising a group of sensors to prevent people and objects from entering hazardous areas. Regularly monitoring and maintaining the safety system will help ensure that the system operates safely and reliably.

Figure 10: Rack 1 High Voltage Panel

Light Curtains​

Light curtains consist of two (2) components mounted across from each other: the transmitter and the receiver. Each component is wired independently back to the main Low Voltage (LV) cabinet via standard 5 pin M12-A cables. These cables connect to the bottom side of each curtain component.

The light curtains protecting the hallway entry and exit are wired in series. In this configuration, an available port on the top of each receiver and transmitter is populated with a connection cable that runs over to the bottom side of the entry receiver and transmitter. This allows the entry and exit curtains to act as a single unit to simplify the wiring required back to the LV cabinet.

Light curtains are secured to the safety fencing posts with qty (2) self-tapping screws (M10 socket). Light curtain brackets have 2 screws on the top and bottom allow the curtain to pivot to align with the mating transmitter/receiver.

To remove a light curtain, remove the top and bottom (if equipped) connection cables, and the top and bottom self-tapping screw from the fence post. The newer GL-V series light curtains uses a different bracket style that allows the curtain to be removed by loosening the front screw at the top and bottom brackets and carefully popping the curtain out from the front.

When receiver and transmitter are in proper alignment, green LEDs will illuminate along the length of the receiver side of the curtain pair. When the curtain is obstructed, this LED array will turn red. As the obstruction is removed, the LEDs will return to green immediately.

Robot Cell Light Curtain​

The robot area light curtain functionality can be confirmed any time the system is operational. When the red light is shining across the entryway, the curtain is armed. By placing an object through the curtain path, the following actions should occur:

  1. Robot entryway red light will begin flashing.

  2. Robot will immediately stop.

  3. The “click” of the joint motor brakes being applied can be heard.

  4. The HMI will display the fault.

If any of these actions does not occur, further investigation and maintenance should be performed to correct any issues.

Figure 11: Robot Area Light Curtain

Hallway Light Curtains​

The light curtains at the front and back of the forklift hallway are armed after an operator has initiated a swap sequence and the red lights appear across the openings in a solid color. By placing an object through the curtain path during this sequence, the following actions should occur:

  1. Both hallway entry and exit red lights will begin flashing.

  2. Robot will immediately stop.

  3. The “click” of the joint motor brakes being applied can be heard.

  4. The HMI will display the fault.

Figure 12: Hallway Light Curtains

If any of these actions do not occur, further

investigation and maintenance should be carried out to correct any issues.

Light Curtain Alignment​

As of June 2025, there are two versions of light curtains in the field.

To align the original “GL-R” light curtains:

  1. Locate the alignment tool (Keyence #). This tool slides onto the top of the curtain and provides a laser sight to the mating side of the curtain.

  2. Turn on the laser and ensure that the laser hits the opposite side of the curtain.

  3. To adjust this alignment, loosen the two (2) socket head screws on the top and the bottom of the curtain brackets and pivot the curtain until the laser is shining on the opposite curtain.

  4. Retighten the socket head screws and ensure that the laser is still aligned.

  5. Remove the alignment tool, turn the laser off, and return to its storage container.

  6. Verify proper function by observing the LED lights inside of the curtain:

    • a. When receiver and transmitter are in proper alignment, green LEDs will illuminate along the length of the receiver side of the curtain pair. When the curtain is obstructed, this LED array will turn red. As the obstruction is removed, the LEDs will return to green instantaneously.

To align the new standard “GL-V” light curtains,

  1. Check to see if the green LED array is green or red. If Green, the light curtains are in alignment.

  2. If the curtains are red, loosen the two brackets holding the light curtain in place and rotate until the entire length of the curtain is showing red. The fewer the red lights, the less in-alignement the curtains are.

  3. Proceed with loosening and rotating the opposite side until all LEDs show red. Step out of the path of the curtain and confirm that the lights turn green.

  4. Finally, retighten the screws holding the curtains to the brackets.

GL-R Light Curtain Replacement​

To replace a GL-R series light curtain:

  1. First ensure that a transmitter is being replaced with a transmitter of the same size, likewise, ensure that a receiver is being replaced with a receiver of the same size.

  2. Remove the top and bottom 6mm hex head screw holding the brackets to the safety fence posts. Be careful not to stress any cabling that is currently attached.

  3. Once the curtain is free, locate the 2 flat head screws on the back of each mounting bracket. Loosen these screws so the bracket slides freely and slide the bracket off the main body of the curtain.

  4. Next, remove any cables attached to the top or bottom of the curtain by loosening the two (2) screws securing the cabling using a Phillips head screwdriver. The screws are captive and will remain with the cables.

  5. At this point, the curtain receiver or transmitter are able to be completely removed from the system.

  6. To replace the curtain, perform the steps above in the opposite direction, paying special attention to the mounting orientation of the curtain.

  7. Perform an alignment check to ensure proper function of the curtain.

GL-V Light Curtain Replacement​

To replace a GL-V series light curtain:

  1. First ensure that a transmitter is being replaced with a transmitter of the same size, likewise, ensure that a receiver is being replaced with a receiver of the same size.

  2. Unscrew the electrical M12 connections from the bottom (and top if equipped). 3. Loosen the top and bottom screw holding the curtain to the brackets.

  3. Carefully pop the curtains out of the brackets.

  4. To replace the curtain, perform the steps above in the opposite direction, paying special attention to the mounting orientation of the curtain.

  5. Perform an alignment check to ensure proper function of the curtain.

Floor Scanner​

The floor scanner constantly monitors the floor area of the robot zone to check for any obstructions that were not present at system commissioning. This scanner is electrically connected to the system with a cat5e ethernet cable and a standard 4 pin M12-A cable. The scanner is mounted to a bracket on the bottom right corner of the rack using four (4) M8 screws. To replace the scanner, simply disconnect the two (2) electrical cables, and remove the four (4) M8 screws.

The floor scanner used is a Keyence SZ-V series scanner. All Daily and Annual checks should be completed following the procedures located in the Keyence SZ-V User Manual (Keyence document number AS 116131). For reference, those steps can be found in

The floor scanner is active at all times except when the robot is in Teach Mode. The floor scanner will display 3 colors on the top display unit:

  • Green indicates that there are no obstructions inside of the robot zone.

  • Orange indicates that there are no objects in the protected zone of the robot but an object is detected in the hallway. This can be a forklift, person, or other object inside ait tr Te . of the forklift hallway. An orange indicator | ,

  • will not affect the functionality of the system.

  • Red indicates that there is an obstruction inside of the protected robot area that will prevent the robot from moving. Removal of the object out of the protected zone will result in an orange or green light.

Testing of this scanner in an armed state can be

accomplished by placing an object underneath

the fencing to trip the system. By placing an object in the scanner protected zone, the following actions should occur:

  1. Robot will immediately stop.

  2. The “click” of the joint motor brakes being applied can be heard.

  3. The HMI will display the fault.

If any of these actions does not occur, further investigation and maintenance should be performed to correct any issues.

Floor Scanner Replacement If one of the two floor scanners inside of the cell is damaged, a replacement should be installed with a new unit with the same part number as the damaged unit. To replace a scanner:

  1. First, power off the safety system breaker inside of the low voltage panel. This breaker is labeled “CB-E0304.”

  2. Next, remove the four M8 socket head caps screws holding the scanner onto the mounting bracket. The mounting bracket can remain in place.

  3. With the scanner removed from the bracket, the connection cables can be disconnected from the unit.

  • a. The main scanner unit attached t

  • Rack 1 will have three (3) connections. These can be removed with a Phillips head screwdriver.

  • b. The secondary scanner head on the opposite side of the robot cell as the main unit only has one (1) connection. This can be removed with a Phillips head screwdriver.

    1. Replace the damaged unit with a new unit, reinstalling the same connection cables as the damaged unit.
    1. Reinstall the new unit to the mounting bracket. 6. Turn the safety system breaker back on and verify that both scanner heads are illuminated green when standing outside of the cell. a. System may need to be reconfigured. See the commissioning section of the installation manual for further details on system setup.
    1. If either scanner head shows a red light when standing outside of the cell, ensure that all cables are secured out of the scanner’s view and that there are no foreign objects inside of the cell.
  1. If the robot area is clear and either scanner head has a red light illuminated, refer to alignment section above to recalibrate the scanner.

Rack Door Magnetic Locks​

The door locks on each rack are controlled electronically by way of an electromagnet. If any door is opened (forced entry), the robot will avoid the rack via the “keep out zone” set in the robot controller. The door locks mounted on the rack side include an LED indicator to display lock state. The following colors can be observed when viewing the inside of the doors from the hallway:

  • Red – Both rack doors are open. This will result in the robot avoiding the rack.

  • Orange – One of the two rack doors is open. The right and left doors are connected in series. This will result in the robot avoiding the rack.

  • Green – Both doors are closed. This is a normal operating state.

An open door will not shut the system down since the robot will simply avoid the area around the rack. The HMI, however, will indicate an open door on the System Health screen.

Figure 16: Door Lock Electromagnets

Door magnetic locks consist of two (2) components: the main electromagnet mounted to the rack side, and a mating round magnet mounted to the door. Replacement instructions for these components can be found in Section 5.5.1.1.

See Magnetic Lock Installation instructions in 4.4.1.1

See Magnetic Lock Replacement instructions in 4.4.1.1

Emergency Stop Buttons​

There is a minimum of two emergency stop buttons placed around the system. The primary locations are:

  • To the left of the HMI screen on the LV cabinet.

  • On the safety fence at the hallway entrance opposite the LV cabinet

For the button next to the operator HMI, this button will not be illuminated during normal operation. When pressed, the light will begin flashing red. This should correspond to an ESTOP message on the HMI as well as immediate stop in motion of the robot.

For the “external” ESTOP located at the entryway of the forklift hallway, an indicator on button housing will be illuminated solid green during normal operation. When pressed, the light will turn solid red. This should correspond to an ESTOP message on the HMI as well as immediate stop in motion of the robot.

If pressing either of these buttons does not cause the robot to stop moving, further investigation should be performed to find the root cause.

Fencing​

The fencing kits are composed of yellow posts bolted to the ground and framed wire mesh panels attached between posts.

Figure 17: Hallway Entry Emergency Stop

Fence Panel Replacement

To replace a mesh panel:

  1. Locate and loosen (removal of the screw is not required) the 4 screws (2 on each side) securing the panel.

  2. The panels can then be lifted up and out of the slot as shown in the image.

Fence Post Replacement To replace a fence post:

Figure 18: Fence Panel Attachment

  1. First remove any mesh panels attached to the affected post.

  2. Remove the QTY 4 – 3/8”x3” concrete screws securing the post to the floor.

  3. Install a new post using the same holes in the floor.

  4. Reinstall the mesh panels to the post.

Figure 19: Fence Post Foot