Teknic SC4-HUB Jumper Configuration and Loopback Check

The red jumper on a Teknic SC4-HUB sets the communication loopback point for the number of motors connected to that hub. An incorrect jumper position can prevent one or more Teknic motors from communicating correctly.

Electrical safety: Power down and lock out the machine before opening the enclosure or moving the jumper. Do not move a jumper while the SC4-HUB is energized.

Jumper selection

• J0 — one motor, commonly the kicker.
• J1 — two motors.
• J2 — three motors.
• J3 — four motors.
• J5 — communication continues to another SC4-HUB rather than looping back at this board.

Count the motors physically connected to the hub and include any continuation to another hub before selecting the jumper. Do not choose a position based only on the number of motor cables visible from one side of the enclosure.

Loopback indicator

The following image shows a working Teknic communication board. The orange light identifies the active loopback point; this example represents a one-motor configuration.

The second image provides another working SC4-HUB and loopback-indicator reference:

Inspection and correction

1. Record the current jumper position and motor connections.
2. Lock out the machine and verify that control power is off.
3. Confirm that the jumper is fully seated on the correct pair of pins and is not offset by one position.
4. Inspect the hub connectors and cables for looseness, damage, or contamination.
5. If the hub continues to another SC4-HUB, verify the continuation cable and use J5 on the upstream board.
6. Restore power only after the enclosure is clear and all connectors are secure.

Verification

• The expected orange loopback indicator is illuminated.
• Every motor connected through the hub appears online.
• No Teknic communication or motor-disconnected warning remains.
• Each associated movement responds correctly during a controlled functional test.

If the loopback indicator is correct but a motor remains offline, inspect that motor’s power supply, status LED, Molex connector, and communication cable before replacing the SC4-HUB.