GE Multilin L90 Line Differential Relay 3-233 HARDWARE 3.3 L90 CHANNEL COMMUNICATION33.3.4 G.703 INTERFACEa) DESCRIPTIONThe following figure shows the 64K ITU G.703 co-directional interface configuration.The G.703 module is fixed at 64 kbps only. The SETTINGS ! PRODUCT SETUP !" DIRECT I/O !" DIRECT I/O DATARATE setting is not applicable to this module.AWG 22 twisted shielded pair is recommended for external connections, with the shield grounded only at one end. Con-necting the shield to Pin X1a or X6a grounds the shield since these pins are internally connected to ground. Thus, ifPin X1a or X6a is used, do not ground at the other end. This interface module is protected by surge suppression devices.Figure 3ñ24: G.703 INTERFACE CONFIGURATIONThe following figure shows the typical pin interconnection between two G.703 interfaces. For the actual physical arrange-ment of these pins, see the Rear Terminal Assignments section earlier in this chapter. All pin interconnections are to bemaintained for a connection to a multiplexer.Figure 3ñ25: TYPICAL PIN INTERCONNECTION BETWEEN TWO G.703 INTERFACESPin nomenclature may differ from one manufacturer to another. Therefore, it is not uncommon to seepinouts numbered TxA, TxB, RxA and RxB. In such cases, it can be assumed that ìAî is equivalent to ì+îand ìBî is equivalent to ìñî.b) G.703 SELECTION SWITCH PROCEDURES1. Remove the G.703 module (7R or 7S):The ejector/inserter clips located at the top and at the bottom of each module, must be pulled simultaneously in orderto release the module for removal. Before performing this action, control power must be removed from the relay.The original location of the module should be recorded to help ensure that the same or replacement module is insertedinto the correct slot.2. Remove the module cover screw.3. Remove the top cover by sliding it towards the rear and then lift it upwards.4. Set the Timing Selection Switches (Channel 1, Channel 2) to the desired timing modes.5. Replace the top cover and the cover screw.NOTE831727A2-X1.CDRXXXXXXXXXXXX8a8b7RRx +Tx +Shld.Tx –Shld.Rx –Tx –Rx +Tx +Rx –COMM.2b6a7a1b1a3a6b7b2a3bG.703CHANNEL 2G.703CHANNEL 1SURGESURGE831727A2.CDRXXXXXXXXXXXX8a8b7RRx +Tx +Shld.Tx -Shld.Rx -Tx -Rx +Tx +Rx -COMM.2b6a7a1b1a3a6b7b2a3bG.703CHANNEL 2G.703CHANNEL 1SURGESURGEXXXXXXXXXXXX8a8b7RRx +Tx +Shld.Tx -Shld.Rx -Tx -Rx +Tx +Rx -COMM.2b6a7a1b1a3a6b7b2a3bG.703CHANNEL 2G.703CHANNEL 1SURGESURGENOTE
