What the 0x000038 alarm means

The controller lost its bus link to one or more joint modules; the robot is stopped until the link recovers. We are very familiar with this alarm on JAKA Zu / JAKA Pro cobots (APP) systems — usually the first on-site inspection is enough to confirm the cause.

Most common causes

  • Bus cable or slip-ring wear in the base
  • Joint module power dip
  • Connector oxidation or looseness
  • EMI on the internal bus
Field note: Our ticket data shows the first cause is by far the most common — start there to avoid dead ends.

Step-by-step field fix

  1. Power-cycle and note whether the same joint drops out
  2. Inspect external cables and connectors
  3. Check for sources of interference near the cell
  4. Update controller and joint firmware to matched versions
  5. Replace the cable or joint module if the dropout repeats
Safety first: For JAKA 0x000038, when communication drops, controller and external devices can disagree about state; at reconnect, external axes or tooling may act on stale commands. On site you may look at after confirming power-off the first step yourself: Power-cycle and note whether the same joint drops out. Beyond that it is external axes and tooling interlocks work - leave it to a professional.

How we diagnose communication alarms on site

JAKA 0x000038 belongs to the communication family. On JAKA 0x000038 the failing stage is JAKA collaborative robot cabinet - the data link: fieldbus, Ethernet, cabinet-to-body communication and external device interfaces. We start reading JAKA 0x000038 at the pendant and app alarm pages; codes are hexadecimal with a 0x prefix.

The chain involved in JAKA 0x000038 runs: physical layer (cable / connector / shield) -> link layer (protocol / baud / node ID) -> application layer (data mapping / handshakes).

If JAKA 0x000038 appears only when talking to external devices: When the alarm appears only in traffic with a PLC, vision system or host, the fault usually sits in application-layer mapping and handshake timing: wrong signal addresses, wrong handshake order, timeouts set too tight. We capture signal states on both the robot side and the device side and see which one fails to act as expected. This is not a hardware fault; it needs both sides adjusted together, usually alongside the customer's electrical engineer.

Field notes on this page cover JAKA 0x000038 (Joint Communication Lost); written by the Henghuan repair team, updated 2026-10-01.

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Related Communication alarms

0x000030 — Controller Temperature Too High 0x000031 — Bus Voltage Abnormal 0x000032 — Motor Overcurrent 0x000033 — Encoder Fault 0x000034 — Motor Overtemperature 0x000035 — Collision Detected
Same family: this code belongs to the Communication alarms family - the page collects all Communication-family codes we have handled, with the common inspection order and spares.
Other brands: we also keep field-fix libraries for AUBO · ROKAE · Dobot and more — see the complete alarm code hub.

Frequently asked questions

QWhat does the JAKA 0x000038 alarm mean?

The controller lost its bus link to one or more joint modules; the robot is stopped until the link recovers. We are very familiar with this alarm on JAKA Zu / JAKA Pro cobots (APP) systems — usually the first on-site inspection is enough to confirm the cause. JAKA 0x000038 sits in the communication family; on our work orders the highest-frequency trigger for this code is "Bus cable or slip-ring wear in the base".

QCan I clear a JAKA 0x000038 alarm myself?

Whether JAKA 0x000038 clears on its own depends on the outcome of "Power-cycle and note whether the same joint drops out". Finish the flow with "Replace the cable or joint module if the dropout repeats" to confirm JAKA 0x000038 - do not skip it. If that step is clean, the second most frequent cause on JAKA 0x000038 is "Joint module power dip". If JAKA 0x000038 returns after two clears, or the checks point at Bus cable or slip-ring wear in the base, stop the cell and call a professional robot repair engineer.

QFor communication alarms like JAKA 0x000038, how long does a site visit take?

The commonest causes we see on JAKA 0x000038 are "Bus cable or slip-ring wear in the base, Joint module power dip, Connector oxidation or looseness", so we stock the van against those. For JAKA 0x000038 specifically, we carry common bus cables, connectors, termination resistors and shield terminals. For JAKA 0x000038, communication work is about tracing the physical link segment by segment; most cases close in one visit. Before we roll, tell us what JAKA 0x000038 shows on the pendant and app alarm pages; codes are hexadecimal with a 0x prefix and what the machine was doing - phone or video triage is free.

This page on JAKA 0x000038 was compiled from actual repair records of the Henghuan Robotics repair team. Alarm notes are our own summary for troubleshooting reference only and may vary with controller and software version — please consult JAKA documentation or contact us if in doubt. Henghuan is an independent service provider, not affiliated with or endorsed by JAKA.