Remote Jog Handle - How it Works and Troubleshooting Guide

How it Works

The Haas Remote Jog Handle (RJH) is an optional component for Haas CNC Machines. To date, Haas has produced three different versions of the RJH: a simple, easy-to-use non-display version [1], a monochrome LCD version [2], and a version with an enhanced color LCD display [3].

The Enhanced Color RJH features a color LCD display and controls for increased functionality like setting tool and work offsets as well as jogging all axes. It also features a high-intensity LED flashlight and magnifying glass for part inspection.

The RJH connects at the Serial Keyboard Interface PCB and takes its power, +5 VDC, from the same PCB. The Serial Keyboard Interface PCB also sends RJH signals to the Maincon.

The LCD and Enhanced Color RJH versions are sealed units and do not have serviceable parts.

An RJH without a display is only capable of jogging axis, and does not have to be replaced as a complete assembly. Go to Haasparts.com to see what components can be replaced.

Symptom Possible Cause Corrective Action Section
Alarm 546 SERIAL KEYBOARD BUFFER OVERFLOW, or none of the functions of the RJH work. There is a bad connection at the RJH Serial Keyboard Interface PCB or at the Maincon/MOCON. Check the cables and connections. 1
There is a faulty Serial Keyboard Interface PCB. Test the RJH for issues. 2
The Axis dial selector fails to activate the selected axis. There is a bad connection at the RJH Serial Keyboard Interface PCB or at the Maincon/MOCON. Check the cables and connections. 1
The switch selector has been damaged or contaminated. Check the RJH for damage or contamination. 3
The Jog Increment selector does not activate the selected increment. There is a bad connection at the RJH Serial Keyboard Interface PCB or at the Maincon/MOCON. Check the cables and connections. 1
The switch selector has been damaged or contaminated. Check the switch selector for damage or contamination. 3
The Jog Handle pulse encoder does not generate axis movement. There is a bad connection at the RJH Serial Keyboard Interface PCB or at the Maincon/MOCON. Check the cables and connections. 1
There is a faulty or contaminated Jog Handle Pulse Encoder. Check the jog handle for signs of contamination or physical damage. 4
The Start or Feed Hold buttons fail to start the program or hold the feed. The buttons have been damaged or contaminated. Check the RJH for damage or contamination. 3
There is a bad connection at the RJH Serial Keyboard Interface PCB or at the Maincon/MOCON. Check the cables and connections. 1
Axis pause during jogging, or handle does not respond to the first few clicks when starting or changing direction. Normal operation. No action required. 5

Section 1

Symptom: The Axis dial selector fails to activate the selected axis. The Jog Increment selector does not activate the selected increment. The Jog Handle pulse encoder does not generate axis movement. The Start or Feed Hold buttons fail to start the program or hold the feed. None of the functions of the RJH work. Alarm 546 Serial Keyboard Buffer Overflow

Possible Cause: There is a bad connection at the RJH Serial Keyboard Interface PCB or at the Maincon/MOCON.

Corrective Action:

  • Check and make sure that the cable that connects the RJH to the Serial Keyboard Interface PCB is in good condition.
  • Inspect the connections at J2, J3, and P6 on the Serial Keyboard Interface PCB. Reseat the connections.

Section 2

Symptom: None of the functions of the RJH work. Alarm 546 Serial Keyboard Buffer Overflow

Possible Cause: There is a faulty Serial Keyboard Interface PCB.

Corrective Action:

Perform all tests and checks listed in Sections 1-4.

Connect the Jog Handle directly to the MOCON and test all functions.

If the Jog Handle operates properly when connected to the MOCON, the serial Keyboard Interface may be faulty.

Section 3

Symptom: The Axis dial selector fails to activate the selected axis. The Jog Increment selector does not activate the selected increment. The Start or Feed Hold buttons fail to start the program or hold the feed.

Possible Cause: The switch selector has been damaged or contaminated.

Corrective Action:

Examine the buttons [1] and switches [2] for signs of physical damage or contamination.

If there is no display on the RJH, remove the face plate. Check the continuity of the buttons.

Section 4

Symptom: The Jog Handle pulse encoder does not generate axis movement.

Possible Cause: There is a faulty or contaminated Jog Handle Pulse Encoder.

Corrective Action:

Check the Pulse Encoder and look for signs of physical damage or contamination.

Some jog wheels have a set screw. Make sure it is tight.

Section 5

Symptom: Axis pause during jogging, or handle does not respond to the first few clicks when starting or changing direction..

Possible Cause: Normal operation.

Corrective Action:

It is normal operation for the jog wheel to ignore the first few pulses (clicks) when starting or changing axis motion.

On machines that have a Next Generation Control, axis motion will pause if you spin the jog wheel at a high rate.

Make sure you have the latest software installed in your machine.

Be aware: Many service and repair procedures should be done only by authorized personnel. The service technicians at your Haas Factory Outlet (HFO) have the training, experience, and are certified to do these tasks safely and correctly. You should not do machine repair or service procedures unless you are qualified and knowledgeable about the processes.

Danger: Some service procedures can be dangerous or life-threatening. DO NOT attempt a procedure that you do not completely understand. Contact your Haas Factory Outlet (HFO) and schedule a service technician visit if you have any doubts about doing a procedure.

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