LMD222 and LMD224 Series
Operations Manual
Eberle Design Inc.
Page 1
Section 1
GENERAL
1.1 DESCRIPTION
The LMD222 two channel and LMD224 four channel rack-mounted inductive Loop Monitor
with DEFLECTOMETER
®
Series is built on the international card format with double-sided
44 pin edge connectors for connection of power, loop inputs and call outputs. The
DEFLECTOMETER
®
push-button user interface far exceeds the DIP switch based
requirements of the Caltrans specifications. The LMD222 and LMD224 are compatible with
all 332 type Input Files and is intended as a plug-in upgrade for the Model 222 and 224.
The LMD222 meets or exceeds the applicable performance requirements of the California
Department of Transportation (Caltrans) specifications TEES March 2009.
Each channel has individual controls for setting up sensitivity, operational mode and
frequency on the front panel. Two high intensity front panel LEDs indicate vehicle detection
and fault monitoring status for each channel. Call outputs are available in either relay or
optically-isolated solid-state transistor form.
1.2 OVERVIEW
A dynamic Overview of the LMD operation which includes an LMD Simulator is available on
the EDI Web Site;
1.3 DEFLECTOMETER
®
FEATURE
The LMD Series Loop Monitor introduces a concept to the inductive loop detector field that
revolutionizes the process of installing and programming a loop detector. The new user
interface of the LMD Series provides the feedback necessary to the signal technician to
quickly and accurately program the parameters of the detector exactly to the loop plus lead-
in system characteristics.
Loop diagnostic capabilities incorporated within the LMD Series Loop Monitor enable the
detection of short or open circuit loops and sudden changes of inductance exceeding 25
percent of the nominal inductance. Each type of fault is signified by the fault indicator
emitting a different flash sequence. This information can greatly assist the user in the
diagnosis of loop related problems.
Why guess when you can know!
The DEFLECTOMETER
®
display shows the relative strength of the call
while a vehicle is in the detection zone. This provides feedback that the
unit is optimally tuned to detect vehicles of all sizes.
Setting the sensitivity level of the detector can be easily done in one step
with a “typical” vehicle parked in the detection zone. The
DEFLECTOMETER
®
display updates dynamically as the sensitivity level is
changed. See section 2.1.1.
The simple push-button interface is intuitive and eliminates many of the
reliability problems found with tiny DIP switches of conventional detectors.
Operational mode, Frequency, and Sensitivity are all programmed and
displayed using the push-button interface. Settings are stored in non-
volatile memory.
