What the 0x40 alarm means

Joint 1 moved to its positive limit zone; per the Dobot ALARM description, moving back out of the limit zone clears this alarm automatically. This is one of the faults our repair team handles on Dobot Magician / MG400 / M1 / CR (DobotStudio) systems — the cause is usually identifiable within the first on-site inspection.

Most common causes

  • Jog or program drove joint 1 to its positive end of travel
  • Taught point too close to the limit
  • Accumulated offset pushing the axis to the end
  • Wrong home reference after maintenance
Field note: the first item on this list is what we find most often on real machines. Check it before you go deeper.

Step-by-step field fix

  1. Jog joint 1 back in the negative direction — the alarm resets automatically
  2. Re-teach points that sit at the limit with margin
  3. Check for unintended offset accumulation
  4. Verify home/zero reference after any maintenance
  5. Re-run the program and watch the limit margin
Safety first: never bypass safety circuits or force contactors closed. If the alarm involves E-stop chains, brakes or drive power, and you are not a trained robot technician, contact a professional — wrong moves here can cost you a robot or an injury.

Still stuck? Get an engineer on the phone — right now

Tell us the alarm code, the robot model and what was happening when the alarm came up. Our engineers run these diagnostics every day, and remote diagnosis by phone or video call is free.

Get a Free Remote Diagnosis See Repair Services

Hotline: +86-20-39029800 · WhatsApp: +86-188-1886-2860

Related Motion & Path alarms

0x20 — Inverse Kinematics Singularity 0x21 — Inverse Kinematics No Solution — Out of Workspace 0x22 — Inverse Kinematics Over Joint Limit 0x30 — Joint 1 Overspeed 0x31 — Joint 2 Overspeed 0x32 — Joint 3 Overspeed
Other brands: we also keep field-fix libraries for FANUC · KUKA · ABB and more — see the complete alarm code hub.

Frequently asked questions

QWhat does the Dobot 0x40 alarm mean?

Joint 1 moved to its positive limit zone; per the Dobot ALARM description, moving back out of the limit zone clears this alarm automatically. In field practice it belongs to the motion & path family of faults.

QCan I clear a Dobot 0x40 alarm myself?

Sometimes. Work through the step-by-step checks on this page — the first listed cause is what we find most often in the field. If the alarm returns after two attempts, or the fault involves power, brakes or safety circuits, stop and call a qualified robot service engineer.

QHow fast can a Henghuan engineer help?

On-site response in the Pearl River Delta within 30 minutes to 3 hours, across mainland China in 1-3 business days, and worldwide within 2-5 business days. Remote diagnosis by phone/WhatsApp/video is available immediately.

Written by the Henghuan Robotics repair team from field service experience. Alarm descriptions are our own summary for troubleshooting reference and may vary by controller and software version — when in doubt, check your Dobot documentation or contact us. Henghuan is an independent service provider, not affiliated with or endorsed by Dobot.