Browse Prior Art Database

Loop Continuity and Relay Tester

IP.com Disclosure Number: IPCOM000086696D
Original Publication Date: 1976-Oct-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 89K

Publishing Venue

IBM

Related People

Checkley, CH: AUTHOR [+3]

Abstract

Fig. 1 shows testing circuits in tester 17 for verifying the correct wiring of a loop communication system having a main loop pair of wires 11 and an auxiliary loop pair of wires 13, all within a shielded cable. Terminal connection boxes 15 are provided to connect the main loop to a terminal during normal operation and to bypass faults using portions of the main loop and portions of the auxiliary loop. Four-pole double-throw switch 1 performs a wrap-left function and four-pole double-throw switch 2 performs a wrap-right function. (Fig. 2 of U. S. Patent 3,569,632 shows an example of wrapping at terminals on either side of a fault to isolate the fault.

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Loop Continuity and Relay Tester

Fig. 1 shows testing circuits in tester 17 for verifying the correct wiring of a loop communication system having a main loop pair of wires 11 and an auxiliary loop pair of wires 13, all within a shielded cable. Terminal connection boxes 15 are provided to connect the main loop to a terminal during normal operation and to bypass faults using portions of the main loop and portions of the auxiliary loop. Four-pole double-throw switch 1 performs a wrap-left function and four-pole double-throw switch 2 performs a wrap-right function. (Fig. 2 of U. S. Patent 3,569,632 shows an example of wrapping at terminals on either side of a fault to isolate the fault.) The terminal connection boxes 15 also have the capability of wrapping the terminal connecting receive and transmit pairs so that Ris connected to Tand R- is connected to T- to test the transmit and receive as functions of the terminal itself.

Tester 17 has momentary single-pole single-throw switches TS-2 and TS-3 to individually pick relay 1 and/or relay 2 to insure proper operation of these relays. Tester 17 also has a two-pole, seven-position rotary switch R used in conjunction with voltohmmeter (VOM) 19 for testing the resistance of all the possible combinations of receive and transmit connections to the main loop pair 11 and the auxiliary pair 13 under the wrap conditions and relay conditions shown in tabular form in Fig. 2. By moving the lead of VOM 19 from the jack to the shie...