UserCurrentLimit

General

Type

EF

Offline editable

Yes

Devices supporting the parameter

Lexium MC Carrier

Traceable

Yes

Functional Description

The parameter represents the maximum current in milliamperes rms (mArms) for the carrier, specified by the user. This setting limits the reference current of the carrier, which results in a carrier force limitation.

The resulting force limitation can be calculated using the force constant of the Lexium™ MC12 multi carrier: Force = Carrier current x Force constant

The force constant of a Lexium™ MC12 multi carrier straight segment is 12 N/A and the force constant of a segment arc is 10 N/A (see Lexium™ MC12 multi carrier Hardware Guide).

As the force is calculated by multiplying the carrier current by the force constant, you must divide the force by the force constant to determine the corresponding carrier current.

Example:

  • Required force limit: 5 N

  • UserCurrentLimit = 0.707 × 5 N / 12 N/A = 0.294 A = 294 mA

NOTE: The additional factor of 0.707 is needed because the UserCurrentLimit is defined in Arms but the force constant is defined in N/Apeak.

NOTE: The carrier-specific setting UserCurrentLimit can be enabled through the parameter EnableUserCurrentLimit.
NOTE: The parameter UserCurrentLimit is mapped to the cyclic Sercos data of the carrier so that modifications are possible on the fly.

Unit

Data type

Meaning

mArms

LREAL

The maximum current in milliamperes rms (mArms) for the carrier, specified by the user.