LEM Feedback Troubleshooting & Replacements
- Julianne Mahley (Unlicensed)
- Eric Rojas (Unlicensed)
- Perla Madrigal (Unlicensed)
LEM is obsolete and no longer available. Replacement parts are no longer available, including the readheads, decoder boards DB1A and the calibration kits.
LEM1 was 5um resolution with a maximum speed of 5m/sec. It was used with the 110, 210 and 310 motors.
LEM4 was 7um resolution with a maximum speed of 7m/sec. It was used with the 410 motor.
Both the LEM1 and LEM4 used decoder boards to interpolate the feedback into quadrature feedback.
Recommended replacement: LME5F
LME Improvements:
The LME5F is a 5um resolution readhead, with a maximum speed of 7 m/s. The LME1F is a 1um resolution readhead with a maximum speed of 2.5 m/s. Current requirements are less than the LEM, 100mA for the LME, 700 mA for the LEM. The LMEs are IP67 rated, CE compliant, tighter repeatability (+/- 1 encoder count). The LME does not require external calibration. It gives standard 5vdc quadrature output similar to the LEM. They do not require a decoder board so that control panel space and additional wiring is saved. These are a standard feedback on the IForce positioners and can be purchased as a part from Parker Daedal through your local Parker Automation Technology Center distributor.
The LME uses the LMS magnetic scale, which has a self-adhesive backing.
The limit, home and hall-effect sensors are in a new separate module, the MHED (Modular Hall-Effect Device).As the mounting holes for the readhead and MHED are different and the scale needs to be incorporated into the positioner that currently has the LEM feedback, it would be more cost-effective to consider purchasing a new positioner which will have a full warranty, typically better delivery and new components cables, cable track and bearings that could be worn on the older positioner.
Note that the ML50 uses the MLX-HED-R-x where x is the cable length in meters. The cable exit can be changed from one side or the other by undoing the screws through the top of the module and reversing the cable exit.
Related FAQs: