Hubbell 31200 brochure System Features

System Features

Secure Control — Hubbell’s biphase data transmis- sion scheme and Cyclic Redundency Check code (CRC) prevent false motions and provides for con- trolled shutdowns. Digital messages are checked for address, format, and content before any motion or function is activated. While in motion, check circuits continuously monitor the received message and the quality of the RF carrier signal. Any error or loss of sig- nal integrity will de-energize all controlled functions and apply the brakes.

Frequency Conservation — It is possible to have sev- eral transmitters operating in the same area, on the same frequency, with practically no interference be- cause of different transmission rates for each transmit- ter. The unique address code of each transmitter and receiver assures that only the matching receiver re- sponds to the radio commands. All other signals on the same frequency are ignored.

“QSR” Design — Hubbell’s Quality, Serviceable, Reli- able product design philosophy is evident with the Lo- comotive Control System. Protective circuits are em- ployed to prevent transients or extreme voltage fluctua- tions from damaging components. The modular, solid state design, housed in NEMA 12 enclosures, pro- vides reliable operation and long service life under the most rugged and extreme conditions. Spares re- quirements are significantly reduced by virtue of the shared frequency capability and modular design.

Efficient and Flexible — The high speed data trans- mission technique provides faster and thereby more responsive operation. A lightweight, durable plastic transmitter is comfortable and easy to operate. A manual/remote transfer switch can be provided for isolation between the manual and remote control components.

Security of the received signal and any resulting con- trol actions are safeguarded as follows:

•The received signal must be of the proper frequency.

•The received message must have the proper ad- dress and must be in the correct format.

•The receiver calculated CRC code must be identi- cal to the CRC code calculated by the transmitter and sent as part of each message.

•The preceding items must be met and all transmitter lever switches must be centered before the locomo- tive can be activated and the brakes released.

•To continue or change an energized function, re- quires the receipt of a “valid message” prior to time-out of the message timer (2 sec). If no valid message is received, the system turns all outputs off and applies the brakes.

•Two separate “watchdog timers” assure that all outputs are switched off in case of a receiver malfunction.

Features

Microcomputer

Hubbell’s system uses a single board micro com- puter which converts the biphase data from the ra- dio receiver, decodes and verifies the message by checking for errors. The computer generates the control outputs to the l/O interface boards. The ad- dress and message time interval is user program- mable. A hardware watchdog timer monitors the program operation and resets the processor if the program fails to exe- cute properly.

On-Board Diagnostics

The computer board em- ploys continuous diagnos- tics. System status is dis- played on a two digit al- pha numeric display. Upon power-up, the initial- ization test checks the I/O boards, internal random access memory (RAM), the motion controlling solid state relays, and the pneu- matic system.

When a fault is detected, the computer will stop the locomotive and the error will be displayed. The fault must be corrected before operation can continue.

After initialization, the

watchdog circuit, the solid state relays and the pneu- matic functions are contin- uously monitored. Any op- erational, communications or run mode faults will shutdown the locomotive, apply the brakes, and dis- play a fault code.

Input/Output Board

The l/O board accepts the control outputs from the microcomputer and con- verts them into driving out- puts for the solid state re- lays. The l/O board also accepts input from the sol- id state relays feedback circuits and provides this information to the controller for diagnostic purposes.

Emergency Stop Board

The Emergency Stop board monitors the Emer- gency Stop pushbuttons mounted in the locomo- tive, the main air reservoir pressure, oil pressure, and coolant water tempera- ture. If any of these func- tions are abnormal, a sig- nal is given to the micro to shut down the locomotive and apply the brakes.

DC Solid State Output

Each solid state relay board has eight circuits to drive the 24VDC interfac- ing relays and solenoid valves to control the loco- motive functions.

Electro-Mechanical Relays

Electro-Mechanical Relays are used to control loco- motive direction, throttle, head lamps, and Lintern lights. The Lintern lights provide operations status information for the remote operator.

Sensing Boards

Each sensing board moni- tors up to eight solid state relay outputs and/or pres- sure switches. This pro- vides complete feedback to the micro on relay and pressure switch status.

Receiver Cabinet

The electronics cabinet is of NEMA 12 construction and houses the power supply, the radio receiver, digital decoding logic cards, solid state drivers and the output relays.

The receiver, digital logic decoding circuits and the solid state drivers plug into common card cag- es. Edgemounted LED’s on the circuit boards sim- plify system troubleshoot- ing and maintenance tasks. All modules are re- movable from the front and the card cage is hinged to provide access to backplane wiring.

Solid state drivers or out- put relays operate the lo-