Mitsubishi Electric MR-J2S-A Error AL.8A: Serial communication timeout

Servo amplifier and motor · taken from the manufacturer’s manual, pages cited

Alarm codeAL.8A

Serial communication timeout happens if the communication cable is broken, cycle exceeds parameter No. 56, or wrong protocol is used. The manual's first action is: “Power OFF→ON”

Model
Mitsubishi Electric MR-J2S-A
Display shows
Serial communication timeout (AL.8A)
Type
Alarm code
Source
Manual p. 69

What AL.8A means

Serial communication timeout p. 200

Common causes

  • 1. Communication cable breakage. p. 200
  • 2. Communication cycle longer than parameter No. 56 setting. p. 200
  • 3. Wrong protocol. p. 200

What to do

  1. Power OFF→ON p. 200
  2. Press "SET" on current alarm screen. p. 200
  3. Alarm reset (RES) p. 200
  4. Repair or change communication cable p. 200
  5. Set correct value in parameter. p. 200
  6. Correct protocol. p. 200

Before you service the product, read the safety instructions in the manual p. 3.

If AL.8A is still not resolved

  • contact service / dealer p. 3
    “Do not attempt to install, operate, maintain or inspect the servo amplifier and servo motor until you have read through this Instruction Manual, Installation guide, Servo motor Instruction Manual and appended documents carefully and can use the equipment correctly.”
  • contact service / dealer p. 4
    “Do not attempt to wire the servo amplifier and servo motor until they have been installed. Otherwise, you may get an electric shock.”
Open the manual at page 69 All MR-J2S-A error codes Manual details & download

This page summarises what the manufacturer’s manual says about AL.8A; each statement links to the page it comes from, and quoted lines are copied word for word. It is not a substitute for the manual or for a qualified installer. ManualLib is not affiliated with Mitsubishi Electric. Found a mistake? Report an error.