Table of Contents
1Scope
1.1Rangeofapplication
1.2Applicableelectricalcharacteristics
1.3Applicablemechanicalcharacteristics
1.4Allocationoffunctionalities
2Lineofdemarcation
3Definitionsofinterchangecircuits
3.1Circuit102-Signalgroundorcommonreturn
3.2Circuit102a-DTEcommonreturn
3.3Circuit102b-DCEcommonreturn
3.4Circuit102c-Commonreturn
3.5Circuit103-Transmitteddata
3.6Circuit104-Receiveddata
3.7Circuit105-Requesttosend
3.8Circuit106-Readyforsending
3.9Circuit107-Datasetready
3.10Circuit108/1-Connectdatasettoline
3.11Circuit108/2-Dataterminalready
3.12Circuit109-Datachannelreceivedlinesignal
detector
3.13Circuit111-Datasignallingrateselector
(DTEsource)
3.14Circuit112-Datasignallingrateselector
(DCEsource)
3.15Circuit113-Transmittersignalelementtiming
(DTEsource)
3.16Circuit114-Transmittersignalelementtiming
(DCEsource)
3.17Circuit115-Receiversignalelementtiming
(DCEsource)
3.18Circuit116/1-Back-upswitchingindirectmode
3.19Circuit116/2-Back-upswitchinginauthorizedmode
3.20Circuit117-Standbyindicator
3.21Circuit118-Transmittedbackwardchanneldata
3.22Circuit119-Receivedbackwardchanneldata
3.23Circuit120-Transmitbackwardchannellinesignal
3.24Circuit121-Backwardchannelready
3.25Circuit122-Backwardchannelreceivedlinesignal
detector
3.26Circuit125-Callingindicator
3.27Circuit126-Selecttransmitfrequency
3.28Circuit128-Receiversignalelementtiming
(DTEsource)
3.29Circuit131-Receivedcharactertiming(DCEsource)
3.30Circuit133-Readyforreceiving
3.31Circuit134-Receiveddatapresent
3.32Circuit135-Receivedenergypresent
3.33Circuit137-Transmittedcharactertiming
(DTEsource)
3.34Circuit138-Transmittedcharactertiming
(DCEsource)
3.35Circuit140-Loopback/Maintenancetest
3.36Circuit141-Localloopback
3.37Circuit142-Testindicator
4Operationalrequirements
4.1Datacircuitsandtimingcircuits
4.1.1Datacircuits
4.1.2Timingcircuits
4.2Controlandindicationcircuits
4.2.1Operationofcircuits107,108/1and108/2
4.2.2Circuit125-Callingindicator
4.2.3Usageofcircuit126
4.2.4Circuit140-Loopback/MaintenanceTest
4.3Miscellaneous
4.3.1Interrelationshipofcircuits103,105and106
4.3.2Idleperiods
4.3.3Clamping
4.4Circuitfailures(electrical)
4.5ProvisionofinterchangecircuitsinDCEsandDTEs
4.6Dataflowcontrol
4.7Power-upconsiderations
5References Abstract
Recommendation applies to the interconnecting circuits being called interchange circuits at the interface between DTE and DCE for the transfer of binary data, control and timing signals and analogue signals as appropriate.
