EDI MMU-16E Malfunction Management Unit

EDI’s MMU-16E malfunction management unit manages malfunctions affecting traffic light control cabinets. It displays the cabinet’s status, monitors faulty signals, reports malfunctions and provides accurate diagnoses.


The MMU-16E has two operating modes:

16 channels (Type 16 mode) with 3 inputs per channel (red/don’t walk, yellow, green/walk)
12 channels (Type 12 mode) with 4 inputs per channel (red, yellow, green, walk) with backward compatibility with TS-1989 controller units

Its red, yellow and green LEDs simultaneously display the real-time status of the entire intersection as well as the status of memorized faults for each channel.

It simultaneously detects active green and yellow lights, active green and red lights or active yellow and red lights on the same channel (as well as walk lights in Type 12 mode).

In Type 16 mode, the MMU-16E analyzes the controller unit output commands and field input status to isolate whether the problem was caused by a controller unit malfunction or a failure in the load bay or field wiring, and then identifies the faulty channel and input directly.

Also, in Type 16 mode, it ensures real-time communication with the controller unit using the SDLC protocol to exchange data on field input status, controller unit output status, fault status, MMU programming as well as date and time. It also monitors Port 1 activity.

The MMU-16E comes with RMS-EngineTM, a DSP coprocessor that converts AC input measurements to true RMS voltages thereby virtually eliminating false sensing due to changes in frequency, phase or sine wave distortion.

A non-volatile time-stamped event log provides complete information on intersection status as well as AC line events, configuration changes, management unit resets, temperature and true RMS voltages. Five logs stored in the non-volatile memory also graphically store up to 30 seconds of signal status prior to each fault event.

The built-in EDI ECcomTM Windows software facilitates access to status data, event log retrieval, configuration and data archiving.

The MMU-16E malfunction management unit meets all specifications of the NEMA TS2-2003 standard (Section 4) while maintaining compatibility with NEMA TS1-1989 devices.

General characteristics

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