Sinumerik Alarm 300608 Axis %1 drive %2 speed controller at limit

Sinumerik Alarm 300608 Axis %1 drive %2 speed controller at limit

%1 = NC axis number
%2 = Drive number

The speed controller output is lying for an impermissibly long time at its limit (MD 1605: $MD_SPEEDCTRL_LIMIT_TIME and MD 1606: The torque setpoint has exceeded the torque limit or the current setpoint the current limit. The monitoring system is only active when the speed setpoint is below the speed threshold in MD 1606: $MD_SPEEDCTRL_LIMIT_THRESHOLD. The alarm can be reprogrammed in the MD ALARM_REACTION_CHAN_NOREADY (channel not ready).

– Mode group not ready.
– Channel not ready.
– Channel not ready.
– NC Start disable in this channel.
– NC Stop on alarm.
– The NC switches to follow-up mode.
– Alarm display.
– Interface signals are set.

Please inform the authorized personnel/service department.
• Is the motor blocked, overloaded or the brake closed?
• If permitted by the power section, set the limits for torque, performance and current to higher values.
• Is the motor connected to ground?
• Check the motor converter connection (phase missing, incorrect rotary field).
• Check the encoder resolution.
• Check the encoder, encoder cable and shield connection for loose contact or cable breakage.
• Check the direction of rotation of the encoder tracks (e.g. gearwheel encoder MD 1011: $MD_ACTUAL_VALUE_CONFIG bit 1)
• Is the encoder cable appropriate for the encoder type?
• Check the controller settings (e.g. after software exchange).
• Check the motor protection.
• DC link voltage available?
• Check the DC link connections (check that the screws are tight).
• The Uce monitoring circuit has been activated (perform a reset by switching the power supply off and on again).
• Modify MD 1605: $MD_SPEEDCTRL_LIMIT_TIME and MD 1606: $MD_SPEEDCTRL_LIMIT_THRESHOLD in accordance with the mechanical and dynamic features of the axis.
• Default values for FDD:
• MD 1605 = 200 ms
• MD 1606 = 8000 rpm
• Default values for MSD:
• MD 1605 = 200 ms
• MD 1606 = 30 rpm
• Replace the motor (encoder is defective, motor has a winding or ground fault or a short circuit)
• With linear motors:
• Check actual value inversion.
• Check the reduction of the max. motor current MD 1105 MD_MOTOR_MAX_CURRENT_REDUCTION and increase the value if necessary.
• Check connection of motor cables.
• Are the motors arranged correctly in a parallel circuit and is their electrical interconnection correct?

Program Continuation:
Clear alarm with the RESET key in all channels of this mode group. Restart part program.


  1. Siemens Diagnostics Guide by Siemens
Sinumerik Alarm 300608 Axis %1 drive %2 speed controller at limit