Rack Control Module
TM
Product Manual
Rev. 1.2, May 9, 2014
Page 4
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Introduction and Description
1.3
System Description
1.3.1
The RCM is part of a secondary overfill prevention system. It is an optional accessory
that receives alarm information from the TD80 level transmitter, providing overfill
information to industry standard 5-wire optic and 2-wire thermistor terminal rack
controllers. The RCM may be used on single or two compartment tankers equipped
with a TD80 level gauging system.
The RCM continuously checks one or two TD80 transmitters for overfill or any unsafe
condition to halt the loading process. All conditions must be safe for the RCM to
permit loading. Communication from the TD80 transmitters, vehicle battery voltage,
loaded volume and alarm states are automatically and continuously tested to ensure
a safe and reliable system prior to and during the loading process.
The RCM is compatible with all existing TD80 installation configurations, including
onboard loading pump or bottom loading valve control. It will work with both Dual Rod
and Coaxial Probe TD80 transmitters, multiple Finch displays, MIC 10 interface
device and an external Relay Module for onboard loading control.
The RCM is an upgrade to systems using the P2000 5-wire optic terminal rack
interface. It provides the benefit of both optic and thermistor terminal rack controller
interfaces along with enhanced features to provide maximum safety while loading
hazardous products.
About the TD80 System
1.3.2
The TD80 Level Transmitter is the heart of the TD80 level measurement
system. The TD80 transmitter uses Guided Wave RADAR (GWR) to
measure liquid level in a tank. It does not use any moving parts for level
measurement.
Guided Wave RADAR is a contacting level measurement method that uses a
probe as a wave guide to channel the radio frequency energy to the liquid
being measured. The probe provides an efficient path for t he transmitted
energy and pulse reflections from the surface of the liquid.
The TD80 transmitter measures the time delay between transmitted and
reflected pulses
to calculate distance to the material’s surface. This distance
is then used to determine level of the liquid in the tank.
The calculated level is converted into common volume units and is sent to a
Display such as the Finch 5332 Display. The display is also part of an
optional secondary overfill prevention system. TD80 generated alarms
provide the approaching overfill information to halt loading at industry
standard optic and thermistor controlled loading racks, on-board loading
pumps or valves.
The TD80 system consists of a TD80 transmitter, dual rod or coaxial probe
and a Finch Display. Optional components such as the Finch Relay Module,
horns and lights are installed as required.
