The MDrivePlus Motion Control products represent significant improvements over the legacy MDrives. Based on new patented technology, they feature a richer software command set, improved current control, and enhanced thermal dissipation.

Along with these improvements, there may be situations where the MDrivePlus are not “drop-in replacements” for existing legacy MDrives. Some customers may have software that will not run on MDrivePlus units without syntax modifications. There may be timing differences in some command executions that could affect system response. Additionally, it is recommended that customers with close tolerance or clearance situations study the mechanical drawings for the MDrivePlus units.

The following summarizes differences and steps required to successfully transition an application that uses a legacy MDrive to an MDrivePlus.

Software / Programming Issues

HT Command (Hold Current Delay Time)
The HT command functions differently when transitioning from legacy to plus MDrive units. In legacy units HT=0 will set the delay time to 0, with the unit shifting immediately to holding current percent from run current.

HT=0 in plus units will cause the units to never transition to hold current and the unit will be at the run current percent at all times. HT =1 is the smallest delay time allowable on plus units.

Legacy progams with HT=0 should be modified to HT=1 for the same performance and to avoid issues with motor over-heating.

Commands and Variables:
New commands in the MDrivePlus products were developed to add more programming options for OEMs. Existing legacy MDrive applications that use these new commands for user-defined labels or variables will not run properly on the MDrivePlus products. Legacy MDrive programs that use labels or variables that coincide with new commands need to have those labels or variables renamed.

Here is an alphabetical listing of MDrivePlus commands that should be not be used as a label or variable: