Rack Control Module
TM
Product Manual
Rev. 1.2, May 9, 2014
Page 5
T
P
M
0
0
7
TD80 System Components
1.3.3
TD80 Transmitter
The TD80 transmitter generates and processes the GWR signals to
determine liquid level in a tank. The TD80 is mounted on the tank top and
connected to the probe, is weatherproof and rated for use in hazardous
locations where explosive fumes may be present. TD80s are available in two
versions, dual rod or coaxial probe for compatibility with a wide range of
liquids.
Probe
The probe guides the transmitted pulse and reflection from the surface of the
liquid. Probes are available in dual rod or coaxial versions and require a
matching transmitter type. The probe is mounted on the tank top and is
connected to the bottom of the transmitter. Dual rod probes are designed for
viscous liquids. Coaxial probes are used mostly for tanks containing products
like aviation fuel.
Finch 5332 Display
Finch Displays are available in weather-proof external versions, the Finch
5332E and a smaller internal version, the Finch 5332. Both provide bright
LED numeric display of volume information, alarms and system error codes
from the TD80 transmitter. Various alarm and error conditions are detected
by the transmitter and display. These alarm states control three internal
relays for alarm annunciation, overfill and low level prevention.
Optional Components
1.3.4
Rack Control Module
The RCM is an accessory that enables secondary overfill prevention when
used with industry standard optic and thermistor terminal rack controllers.
The TD80 transmitter sends loaded volume, alarm states and detected errors
by the SV Bus to the RCM, Finch display and optional MIC 10. The RCM
continuously tests the validity of this information; monitors overfill alarms and
send a permissive signal to the terminal rack controller only when all
conditions are safe for loading a hazardous product. Any overfill alarm or
invalid information is intelligently used to determine the correct response.
The RCM continues to monitor the condition for a reasonable and safe time
to allow correct information to be restored. Beyond this time, the RCM
signals a non-permissive to deny loading until correct system operation is re-
established.
False non-permissive conditions caused by product splashing or sloshing are
minimized by the intelligent response of an Information Integrity Check.
Marginal TD80 operation due to probe pitting, fouling or minor damage may
cause a premature halt to loading. These conditions are also considered by
the RCM as part of the intelligent response to maintaining a safe loading
environment. Temporary loss of valid volume information due to sloshing or
minor damage is tolerated in a way that ensures maximum safety near the
overfill level of the tank.
MIC 10
The MIC 10 is an interface device for connecting multiple TD80s to a third
party modem.
