UserMaxVel

General

Functional Description

Used to set the maximum velocity on the drive shaft (gear box outside) and is specified in [units/seconds].

With real axes, the UserMaxVel can be set maximum to the value that corresponds to the maximum motor rotational speed MaxSpeed  [RPM]. With the UserMaxVel parameter, the maximum velocity MaxVel, determined by the system, can be limited. This parameter defines the machine-specific value of MaxVel.

The standard value of MaxVel is overwritten by virtual axes.

If UserMaxVel is set to 0, then the parameter MaxVel is determined by the system.

NOTE:  If the rated speed is exceeded, then the motor picks up less current by increasing rotational speed. The amplitude of the current depends on the momentary voltage in the DC bus. The current is reduced until a further increasing of the speed is not possible anymore. Depending on the EMC of the used motor, it is possible that MaxSpeedLinear cannot be reached (the typical DC bus voltage on a 3-phase 400 V network is 560 V, for MaxSpeedLinear up to 780 V are assumed). Provide that in the requested operating case of a machine enough current can be driven (see Drive sizing with Motion Builder).

UserMaxVel influences the threshold for triggering the diagnostic message 8122 Shutdown due to velocity limit.

NOTE: Modifications to the parameter are only applied during the Sercos phase up (communication phase 0 => communication phase 4). The maximum user speed is not supervised for induction motors without encoder (in open-loop V / f control mode, ControlMode = open-loop control / 1).

The following graphic shows the dependency with other object parameters for rotary drives:

 

 

The following graphic shows the dependency with other object parameters for linear drives:

 

 

Yellow parameters are input parameters, whose values are taken over by the Sercos phase up. Green parameters are input parameters, whose values are taken over immediately. Gray parameters are output parameters. Thick arrows show that a parameter makes an impact on another parameter immediately by the input. Thin arrows show that a parameter does not have an impact until the next Sercos phase up or when the dependent parameter is entered. The arrow indicates the effective direction of the dependency.

Example:

Entering J_Load has a direct impact on the parameter MaxAcc. A revision of MaxAcc only has an impact on ControllerStopDec if,

oa Sercos phase up takes place or

othe parameter ControllerStopDec is modified.