CARRIER TRANSMISSION MAINTENANCE SYSTEM (CTMS) HOT TONE SCAN (HTS) AND QUICK HOT TONE SCAN (QHTS)

Transcription

1 BELLSYSTEM PRACTCES AT& TCa Sttmdard SECTON ssue 2, November 1976 L MULTPLEX COMMON TERMNALS EQUPMENT CARRER TRANSMSSON MANTENANCE SYSTEM (CTMS) HOT TONE SCAN (HTS) AND QUCK HOT TONE SCAN (QHTS) CONTENTS PAGE. GENERAL ACCESS CRCUTS HOT TONE SCAN PROGRAM A. Scheduling HTS Program B. HTS Printout QUCK HOT TONE SCAN PROGRAM. 2 A. Scheduling QHTS effort to locate the cause of the noise. QHTS runs much more rapidly than HTS and routinely makes noise checks on receiving multiplex sections as well as transmitting multiplex sections. The QHTS program falls back on mastergroup access points for measurements if line access is not provided. Both programs can be run on demand with parameter controls This section is reissued to add the QHTS program information, add access circuits, and revise the corrective action procedure. Since this issue constitutes a general revision, arrows ordinarily used to indicate changes are omitted. B. QHTS Printout CORRECTVEACTON GENERAL 1.01 Two routine programs may be used in CTMS to detect noise at line access. The first, hot tone scan (HTS), scans multiplex sections at transmitting line access channel-by-channel for high-level signals. This is a very thorough program since every channel of every transmitting mastergroup is searched for high-level signals. t is also a slow program and is unlikely to detect transient noise problems. A second program, called quick hot tone scan (QHTS), makes measurements of supergroup out-of-band noise slots of both receiving and transmitting multiplex sections at line access. f the average noise in the noise slots of a mastergroup is excessive, a channel-by-channel search of that mastergroup is conducted in an ACCESS CRCUTS 2.o1 The following circuits provide access to multiplex sections at line and at mastergroup. Mastergroup access is used as a secondary access point for routine measurements and may be specified for an HTS demand measurement. Fig. 1 LMX-1 and LMX-2 Multiplex Transmitting Mastergroup and Pilot Access Circuit (U600 Configuration) Fig. 2 LMX-1 and LMX-2 Multiplex Transmitting Mastergroup Access Circuit (L600 Configuration) Fig. 3 LMX-1 and LMX-2 Multiplex Receiving Mastergroup Access Circuit Fig. 4 3A WLEL Transmitting Access Circuit (for TD-2, TD-3, and TH-3) NOTCE Not for use or disclosure outside the Bell System except under written agreement Printed in U.S.A. Page 1

2 SECTON Fig. 5 3A WLEL Receiving Access Circuit (for TD-2, TD-3, and TH-3) Fig. 6 TH-1 Transmitting Access Circuit Fig. 7 TH-1 Receiving Access Circuit Where: pl is short code assigned to a specific line or multiplex section to be scanned. p2 is access point designation. as follows: Fig. 8 L3 Transmitting Access Circuit 2 receiving line Fig. 9 L3 Receiving Access Circuit Fig. 1O L4 Transmitting Access Circuit Fig. 11 L4 Receiving Access Circuit 3 transmitting 4 receiving 5 transmitting line mastergroup mastergroup p3 is always O (enter by default using two commas). 3. HOT TONE SCAN PROGRAM A. Scheduling HTS Program 3.01 The HTS program normally runs as a routine program to scan multiplex sections at transmitting line for abnormally high-level signals. HTS in a magnetic tape storage system is controlled by BOS commands T (to establish an execution time), ON (to initialize the program for routine running, and ON,HTS,NOW... (for demand execution). n a disc storage system, one of two methods of control may be used (1) RTE system commands T and ON as above for routine execution and RU for demand execution, or (2) control by the auxiliary terminal monitor (ATM) program in which HTS is initialized by an 1P command, scheduled by an S command, and run as a demand program by an ON,HTS,NOW... command. The BOS and RTE system commands and the ATM program commands are described in Section HTS maybe called on with parameter control to scan for hot tones at a specific access point. The command to start HTS as a demand measurement program is *on,ht~,now],pl,p2 [,p3,p4 ] in a magnetic tape system or in a disc system when HTS is under ATM program control, OK *Ru,HTs,pl,p2 [,p3,p4 ] in a disc system using only system commands. p4 = O (or absent) noise measurement threshold is O dbmo. p4 > 0 number passed is noise measurement threshold in db below O dbmo. B. HTS Printout 3.03 Figure 12 illustrates a typical printout resulting from running the HTS program. When the voiceband level equals or exceeds the print level (either O dbmo or optionally established by p4 when making a demand measurement), the l-khz test tone and 2600-Hz SF tone levels plus the group pilot deviation are measured and printed as an aid to trouble isolation. A dollar sign ($) is printed whenever a tone to be measured is not detected. 4. QUCK HOT TONE SCAN PROGRAM A. Scheduling QHTS 4.01 The QHTS program normally runs by clock control to detect high-level signals that by intermodulation are causing excessive noise in the supergroup out-of-band noise slots of a multiplex section. f the average noise exceeds the print limit (normally O dbmo), or has increased by 3 db since the last time measured (in a disc system only), the multiplex section is searched channel-by-channel for the high-level signals and significant results are printed. QHTS must be scheduled for routine running by the process described in 3.01 for the HTS program. Page 2

3 1SS2, SECTON 3S QHTS may be called on to run as a demand program; however, only the device to which the output is to be directed is under parameter control. The command to run QHTS as a demand program is: *ON,QHTS[,NOW1,P@2,p3,p4,p5 ] in a magnetic tape system or in a disc system when QHTS is under ATM control, OK *RU,QHTS[,pl,p2,P3,p4,p5 ] in a disc system using only system commands. Where: pl through p4 are always zero (enter by default using commas). p5 is the logical unit number of the desired list device if other than the standard list device. B. QHTS Printout 4.03 Figure 13 is a typical printout of the QHTS program. Often only the multiplex section is printed as being noisy. However, if voiceband (VB) power of a channel in a noisy multiplex section is found to exceed -6 dbmo, that measurement plus those at 1000 Hz and 2600 Hz (SF) plus the group pilot deviation are printed as a troubleshooting aid. 5. CORRECTVEACTON 5.01 Chart 1is a suggested procedure for correcting channel noise detected by HTS or QHTS. When trouble has been cleared, follow local procedures to update the maintenance history file. Page 3

4 .- SECTON KtlZ PLOT WS f \ -El 1 b- SG8K SG OUT MSF W -1 LMX- U600 SO LMX-2 U600 SD-SO 14S-01 1ss 20B SD ss 10s U ;:B: 3 DB 0, Deg135n ~,. 7SQ 2507SA TRNSF 10 l- L. -6o. DEMO - 372A BASC ffi D~ PLOT D13M0, -+) DBTL L> SGSK ~> OUT TST 372A 542A 231D JACK \ 542A 27 De 31 JACK S -40. DBTL b 3.3 HYO CTWS AMPL N 4030A LEGENO: NTERFACE EQUPMENT. JACKS MOUNT?D N JACK PANEL. MG S PL TST 730A N 1 CTM6 b- 477E CA8LC JACK SCL SW Fig. 1 1.MX-1 and LMX-2 Multiplex Transmitting Mastergroup and Pilot AccessCircuit (U600 Configuration) Page 4

5 1SS2, SECTON G.-,,,. LMX- L600 S BAslc m Deu SEL W FOR FUTURE P1LOT BuS ACCESS 73CM CA24E \ -wmbf,1 542A JACK 231D PA V OBTL m A JACK { 477E JACK * SG BK OUT TST.. L372A CTMS M ANO AMPL N PL TST 1 LEGEND: NTERFACE EQUPMENT ctms N L_cs_ 372A Fig. 2 LMX-1 and LMX-2 Multiplex Transmitting Mastergroup AccessCkcuit (L600 Configuration) RCVG REC WT A orec 21.3 OBTL \/ KS-19224, L 11} A 4 b 1r KS-19224, M TRAMS L2 SP SG BK REC \ A -21,9 06TL 0.6 cms 9.6 LMX- U600 S LMX SO LMX-2 SO ss A P/O JACK PNL RCC A ~ T U K N : T--f;r LEGENO: NTERFACE w EOUPMENT 372A 372~ Fig: 3 LMX- 1 and LMX-2 Multiplex Receiving Mastergroup AccessCircuit Page 5

6 .- SECTON T TRMTG SG N S ss TL + \ 23( ) OR 37A ATTEN GN dnon 63E 3-DB OUT 1 448A 2682A TRNW DOM 2682A TRANS so *< T 1ss 18B _ -+3+ PROT ULELA -10 OUT LJBTL LEGEND: NTERFACE fqu PNENT L1 63E 6-OB 448A LF \ 442A 730A PLUS -25 OBTL SE. w Fig. 4 3A WLELTransmitting AccessCircuit (for TD-2, TO-3, and TH-3) Fig. 5 3A WLEL Receiving Access Circuit (for TD-2, TD-3, and TH-3) l- -4 % --G -T 724A r SO SS 60 (TH-1) R0K3Vt TERM. RfS NOl DBTL ffi2-41,s OBTL MG3-38.9,1 730A CABLC DBTL StL SU P/omGEND: JACKWNEL NTERFACE fqu PWNT ~ &TG 7?- + 7 L 7s SD , SS 60 MC DBTL MG DBTL MG DBTL % 724A \ r u WL SW K ) 730A 540A JACK 4771! JACK MG OUT B A ~ CTN5 N * _ P/O * JACK PNL LCGEMD: NTERFACE EWPMEMT d Fig. 6 TH- 1 Transmitting AccessCircuit Fig. 7 TH- 1 Receiving AccessCircuit Page 6

7 1SS2, SECTON AMP ---BOUT p6 FLAT AMR S ss A p/o PAMEL x JACK LEGEND: _ NTERFACE EQUPMENT d Mcl -30 DBN 54a 477E MG N JACK JACK *3-20 D6# TNT; 13 1S1 A A Clnsll 372A f Fig Transmitting AccessCkcuit t PL OUT A b 1 FLAT AMPL O S SS 23D P/O JACK PANEL d %$,u L 9).6 -J 621A A v u TO -+--Q2 730A CA8LE NGl DBTL 477E N DBTL JACK JACK NG OBTL LCGENO: R[CL3 1ST A A CTBSll _ NTERFACE? r EOU PMENT 1. u J 372A Fig Receiving AccessChcuit Page 7

8 SECTON Al To A TRMTG TRMTG LNE B % d o-do SD TO 1ss 730A OETL m,, Q* 560A JACK P/O JACK PNL r 1 1 $ TRMTG A : 4% 443A ACC TO SEL SW 1 1 S lm DB n NEW 220A CONN al TRMecK P/O JACK PNL LNE 1S1 r r cc 1 LEGEND: w NTERFACE EQUPMENT ASS0t9LY 43M19 Fig Transmitting AccessCkcuit RCVGmRCVG S s 1? OLo n P/O JMK B 1S7 T RCVG 1S1-4 WR+-1 PML -K LNE 1S1 u 443A r- CTMS ACC 730A CAOLE TO - 2e.7 OBTL :OM 1SS 2B m TST OUT RCVG + TST r d 560A JACK P/O JACK PNL c 5 LEGEND: NTERFACE EQUPMENT! > RCVG A n LNE TST u ASSEMBLY 43M19 CTMS ACC Pig Receiving AccessCircuit Page 8

9 1SS2, SECTON L~vELs(Dj3Mfj).- DEV(DB) lits:scc, SGo, GPee CH VB...l KtlZoe, SFo,GPGP PLT*o TMEcc $ $ 16:40 TRMTG --LEVELS(DBM13)-- DEV(DR) HTS:SC..SG..GCH.CH VB... lkhsf....sf..gp PLT..TNE.. 7D $ :50 TRMTG --LEVELS (D BMPJ)-- DEV(DR) HTS:SC..SG..GCH.CH VB ** lkhz.....gpo.gp PLT..TME :41 TRMTG Pig. 12 HTS Printout of Hot Tone Scan Noise. QHTS: QUCK HOT TONE SCAN SSJE 1 DATE 21 LMT -6 DBM SHORT CODE= 2391 NOSE= 41 LMT= 34 CHANGE: 0 RCVG..SC*S(W(WCH...VROKHZ...SF..GP PLT.DAY.TME 231?1*25*5* : 8 SHORT CODE= 5301 NOSE= 35 LMT= 31 CHANGE: 0 RCVG SHORT CODE= 6EN?2 NOSE= 31 LMT= 28 CHANGE: 0 RCVG SHORT CODE= 9003 NOSE= 41 LMT= 37 CHANGE= 0 RCVG Q!i TS : STOP anon Pig. 13 QHTS Printout of Quick Hot Tone Scan Noise Page 9

10 1 [11 RUN HTS AS [31 RECORD DEMAND 1=1 ON TEST RESULT. a NOSY CHANNEL A FLE PRNTOUT YES * [41 TRMTG [51 REFER RCVG OR RCVG TO TRHTG CHANNEL OFFCE TRMTG * NO YES [71 ADJUST e PER SECTON v [8) RERUN HTS AS DEMANO ~ST < ON NOSY CHANNEL * YES v [101 REFER TO LOCAL TEST BOARD chart 1 Clear Channel Noise Problem