()--------------------------------() | | | The Cross Bar Switching Guide | | [Xbar #5] | |=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=| | By Xbar Switchman | | Courtesy of New York Telephone | | Operating Staff - Plant | ()--------------------------------() Phile #9 of P/HUN Magazine Issue #5 Special thanks to Lord Micro and Seeker who were the people behind the bins. Introduction: ------------- This guide was developed by the Plant Training Center, to provide a ready reference of information that can be used by The Central Office Switchman during the performance of his daily work. Preface: -------- In this part Class "A" reports are only covered. Future issues will have MTF Tests/Class C/Alarms/Trouble Recorder etc. Section #1 - Class "A" Reports ------------------------------ CLASS "A" Reports ----------------- Class "A" troubles are those reported by subcribers. Prompt and complete handling is very important. Propmtness because the subcribers service may be affected and completeness so that the customers service is not impaired a second time for the same reason. If the line is held out of service by euipment note the x-points closed and release the line hold magnet to allow the subcribers service. If necessary a channel plug may be inserted in the junctor switch portion of the linkage in order to release the subcriber's line sooner. The remaining linkage will be help up. So therefore what is done in such problems is to actually trace this held path and analyze to determine why it was held up. To keep Class "A" report to a minimum switchman analyze all trouble recorder cards as soon as they come in and mark each card for missing or false punches and compare with previous cards. In this way repeaters can be spotted quickly and acted upon. Usually switchman activate the continuity and ground test circuit of the markers at regular intervals in order to pick up linkage tip and ring troubles. Using this approach, along with regular testing procedures should keep common euipment troubles to a minimum. Here is a list of Class "A" trouble reports: NDT - No Dial Tone CC - Cant call DCLR - Double Connection-Lift Receiver PS - Permanent Signal COO - Cutoff Outgoing DCO - Double Connection Outgoing CBDT - Cant Break Dial Tone DTWD - Dial Tone While Dialing DCWD - Double Connection While Dialing NAR - No Audible Ring GWN or INTC - Gets Wrong Number of Intercept ATB - All Trunks Busy DA - Dont Answer GB-FB - Gets Busy-False Busy CH - Cant Hear CBH Cant Be Heard NSY - Noisy DTRWT - Dial Tone Returns While Talking XT - Cross Talk COL Clicks On Line BDR - Cell Doesn't Ring DGC - Dont Get Calls RI - Reaches Intercept FRI Fails to Reach Intercept CIE - Called in Error FB - False Busy BRCM - Bell Rings - Cant Meet DCI - Double Connection Incoming CT - Cant Trip Ringing COI - Cut OFf Incoming FDA - False Dont Answer Here are the explanations of Class "A" troubles occurances: NDT --- 1) Open between HMDF and L.Lk. Frame. 2) Open L relay; Loose connection on L relay; open T or R connections on L.Lk. Frame; Open hold magnet. 3) Paritially Energized L relay or Hold Magnet. 4) Hold magnet help operated. 5) Dirty contacts or no follow on line hold off normal contacts. 6) Line switch and junction switch cross points . 7) If heavy reports from one frame check LLMC. 8) Review trouble cards for DT Marker Trouble. 9) Routine Originating Registers for dial tone. DCLR ---- 1) Check for bent select fingers on L.SW & all J.SW's. 2) Check for false operation of 2 or more line hold magnets on Incoming and Outgoing calls. 3) Review trouble cards for DT markers - especially "X" indicators 4) Review trouble cards on DT markers for LXP or JXP indicators. PS -- 1) Shorted T & R. 2) False ground on ring side. 3) If Linkage fails to release-trace and check for linkage or PSHT trouble. COO --- 1) Loose Connection on T, R or S lead. 2) Poor make of L.Lk Cross Points. 3) Poor make of hold magnets off normals 4) Review Completing Marker Trouble cards for LXP type trouble o outgoig calls. 5) If heavy reports from 1 line link frame check LLC. 6) Possible Pretranslator or PRTC Trouble DCO --- 1) Inspect for cross T & R. 2) Inspect for bent select fingers or 2 selectes operated. 3) Inspect for 2XPTS Closed on same horizontal. 4) Check Comp. MArker Touble Cards (for "X" indications) 5) Check Comp. Marker Trouble Cards (for LXP; JXP indications) 6) Possible doulbe wiring on trunks apperance on TLK frame. 7) False SL inidications. CBDT ---- 1) Possible hihg resistance on subcribers line. 2) Routing Originating registers (DT Test). DTWD ---- 1) Loose sleeve connection. 2) LLK XPTS poor sleeve conection. 3) False release of O.R 4) Pretranslator. DCWD ---- 1) Crossed T or R. 2) False selected bar operation. 3) Bent select finger. NAR --- 1) Trunk pre-trip. 2) Stuck sender or register. 3) subcriber class of service wiring. 4) Out sender link X-Points. 5) Wrong TB-TG wiring of Outgoing Trunk. 6) Wrong RN trunk X connection. 7) Wrong trunk options. 8) Trasverter-Transverter Connector. 9) Recorder. At terminating end: 1) Ringing selection switch. 2) Incoming Trunk Wiring. 3) Linkage. GWN or INTC ------------ 1) Loose tip and/ or ring. 2) Unbalanced subcriber line. 3) Marker Wiring and Number group wiring. 4) Originating register or outgoing sender trouble. 5) Wrong TB-TG-RN Trunk or TLK frame. 6) FAT frame wiring DA -- 1) Incoming register trouble. 2) Ringing selection switch trouble. 3) Wrong NG Wiring. 4) Incoming trunk R Relay adjustment. 5) Open T or R from Incoming trunk to called subscriber. 6) Outgoing trunk supervision trouble. GB-FB ----- 1) Might be overflow instead of busy. 2) Outgoing trunk trouble. 3) Wiring number group wiring. 4) Ringing selection switch trouble. 5) Incoming Trunk wiring 6) Troulbe release by Marker. CH -- 1) Subcriber's line has high resistance. 2) Swinging or poor wiring connections-tip or ring. 3) Dirty X points (tip or ring). 4) Outgoing trunk-poor transmission. CBH --- 1) Subscriber's line has high resistance. 2) Swinging or poor wiring connections tip or ring. 3) Dirty X points (tip or ring). 4) Poor transmissions on trunks. NSY --- 1) Loose Connection tip or ring. 2) Dirty pins on 444 jack on VMDF. 3) Tip or Ring resistance cross. 4) Outgoing trunk transmission. 5) Induction on subcriber's line. 6) Dirty contacts in talking linkage. DTRWT ----- 1) False release of outgoing trunk or incoming trunk euipment. 2) Poor connection or dirty contacts of sleeve lead of talking path. XT -- 1) Before dial tone a) Line link double connection. b) Induction on subcriber's line. 2) After dial tone a) Trunk cable induction. COL --- 1) Vibrating relay. 2) Riding selector. 3) Wiring interference. 4) Improper testing. 5) Loose connection in talking path. BDR --- 1) Open T or R from incoming trunk to subcriber's line. 2) Grounded ring in linkage. 3) Defective incoming trunk. 4) Ringing selection switch trouble 5) Incoming register trouble. 6) Wrong NG or ADF wiring. 7) Check trouble cards for CON and FCG failures on incoming calls. DCG, RI, FRI, CIE ----------------- 1) Number group or ADF wiring. 2) Open sleeve in linkage. 3) Incoming register trouble. 4) Incoming trunk options or wiring. FB -- 1) Possible incoming X'd sleeve. 2) Possible LG relay cross. 3) Possible help up on incoming call. 4) Possible help up by operator. * ITEMS 3 and 4 HOLD CONNECTION WITH CHANNEL PLUG AND MAKE TRACE BACK-IF HELD BY OPERATOR GET REASON. BRCM ---- 1) Open Tip or Ring (T or R ) 2) Unbalanced line. 3) Crossed ring sides. 4) Loose or open sleeve-possible 1 ring. 5) Incoming trunk trouble . DCT --- 1) Crossed sleeves (2 hold magnets) 2) 2 select bars operating 3) 2 LG relays operating. CT -- 1) Defective incoming trunk. 2) Possible high resistance ring side. COI --- 1) Incoming trunk trouble (false release). 2) Loose or dirty contacts of sleeve of incoming connection. FDA --- 1) Reaching wrong #'s possible- see GWN. 2) Ringing selection switch trouble. 3) Incoming trunk trouble. 4) Incoming linkage open T or R. 5) Called sub line open T or R. End of PART 1 ------------- Well this article will conclude on future issues. Hopefully now you have a better understanding of all kinds of troubles reported to the Xbar office. This article is a little complicated to follow and DOES require the basic understanding of No. 5 Crossbar Switching System. Would also like say thanks to Lord Micro and Seeker who were the people behind the bins at a local office. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=