Application Note

Transitioning to MDrivePlus Motion Control from Legacy MDrive

Description

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.

Topics

  • System Upgrade

Applicable Product

  • MDrive Plus

Requirements

Resource Files

Details

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:

A D1-D4 HC L PC SL
AL D9-D12 HI LB PG SM
AS DB HM LK PM SN
AT DC HT LM PN ST
BD DE I1 – I4 LR PR SU
BP DG I5 MA PS TC
BR DN I6 MD PW TE
BY E I7 – I8 MP PY TI
C1 EE I9 – I12 MR QD TP
C2 EF I13 MS R1 – R4 TR
CC EL IC MT RC TT
CE EM IF MV RS UG
CK ER IP O1 – O4 RT UV
CL ES IL O9 – O12 S V
CM EX IH OE S1 – S4 VA
CP FC IN OL S5 VC
CR FD IT OH S7 – S8 VI
CW FM IV OT S9 – S12 VM
D H JE P S13 VR
SF WT


New Command to MDrivePlus
Reserved Word, not accessible


Command syntax changes
:
Command syntax changes may be an issue prior to firmware version 3.004. Units shipped after December 1, 2006 have version 3.004. MDrivePlus products with earlier firmware require a space between the command and value with motion commands, while variable assignments needed an equal sign.

Examples:
Pre ver. 3.004:

Ver. 3.004 and later:

Some MDrivePlus commands vary in execution time from legacy MDrive. Approximate timing for MDrivePlus command execution:

PG addr 282 mSec
PR Mv 1.4 mSec
PR er 1.5 mSec
S 600 mSec

The following times for MDrivePlus are from command entry until the motor begins to move:

MR dist 3.5 mSec
MA pos 3.5 mSec
SL vel 0.7 mSec
HI type 0.7 mSec
HM type 0.7 mSec

 

Electrical Issues

Auxiliary power source through the communication cable MD-CC400-000 is discontinued via IMS Product Advisory dated November 17, 2006. It is recommended that users with existing cable assemblies cover the jack access hole to prevent use. Do not use Communication Ground on Communications Port (P2) for the Auxiliary Power Supply.

The open state of a sinking I/O point for MDrivePlus is now 2.3vdc where legacy MDrive was 5vdc. For example: With S1=0,0,0, the open circuit voltage on I/O 1 will read 2.3vdc.

RS-485 Connector Changes (P2):

10 Pin IDC (RD option)

Signal Legacy MDrive MDrive Plus
TX+ 9 9,1
TX– 8 8,2
RX+ 6 6,3
RX– 7 7,4
Gnd 10 10 – Comm Gnd –
100 Ohms to Motor Gnd
(1–5 no connection) 5 – Aux Power In

 

Mechanical Issues

MDrivePlus products have some dimensional differences from legacy MDrive in regard to housing geometry and overall depth. If the end user’s fit and clearance is in question, careful review of the published mechanical drawings will be required.