Robotics in Manufacturing
SRVO-043

SRVO-043: DCAL alarm (regenerative discharge)

The amplifier couldn't dump all the energy the motors generated while decelerating - regenerative discharge exceeded what can be dissipated as heat.

What it means

The amplifier couldn't dump all the energy the motors generated while decelerating - regenerative discharge exceeded what can be dissipated as heat. Classic on hard-working vertical axes and rapid-fire cycle testing. Reported per amplifier (posts on axes 1-2 or 1-2-3), and needs a power cycle to clear.

Common causes

Ranked by what technicians most often find, most likely first.

  1. Duty cycle too aggressive: frequent hard accel/decel.
  2. Vertical axes generating heavy regenerative energy on the way down.
  3. Amplifier or discharge-resistor circuit fault if it alarms under mild conditions.

How to fix it

  1. Relax the duty: slow the cycle, soften accelerations, add dwell where the program hammers reversals.
  2. Cycle power to release the alarm.
  3. If it persists under conditions the robot previously handled, escalate to the maintenance manual's amplifier checks.

Quick facts

Category
Servo
Affected series
R-30iB; R-30iB Mate; R-30iB Plus; R-30iB Mate Plus
Alarm family
SRVO

Related codes

Verified against FANUC documentation (B-83284EN-1).Last reviewed: 2026-07-09.Editorial process