American Telecom AM64/128A manual

AM64/128A BASE BAND MODEM USER MANUAL A TL Part No. 1/203/002/610 Issue 4 - September 2002.[...]

AM64/128A User Manual 2 THE INFORMA TION CONT AINED IN THIS DOCUMENT IS CONFIDENTIAL TO A TL TELECOM L TD. AND MA Y NOT BE DISCLOSED OR REPRODUCED IN WHOLE OR IN P AR T WITHOUT THEIR WRITTEN CONSENT . ©A TL TELECOM L TD. 2002.[...]

Contents AM64/128A User Manual 3 CONTENTS 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 2. Constructional Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 2.1 Base Band Modems . . . . . . . . . . . . . . . . . . . . . . .[...]

AM64/128A User Manual Contents 4 5.6 Option Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 5.6.1 X.21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 5.6.2 X.21bis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 5.6.3 [...]

Introduction AM64/128A User Manual 5 1. INTRODUCTION This manual applies to the AM 64/128A Baseband Modem. This modem is manufactured in the U.K. by A TL T elecom Ltd. There ar e six variants, each with a differ ent physical data interface circuit. The A TL T elecom Ltd. part numbers for these variants are as follows :- • AM 64/128A - X.21 : 1/20[...]

Constructional Details AM64/128A User Manual 6 2. CONSTRUCTIONAL DET AILS 2.1 Baseband Modems The BBM is housed in a black plastic case. On the front panel ther e is a menu driven LCD display with six keys and five LED's. On the back panel there is a 3- pin IEC mains inlet socket, an input voltage selector switch (230V/120V), a 6-way - 4-loade[...]

System Overview AM64/128A User Manual 7 3. SYSTEM OVER VIEW The AM64/128A baseband modem uses the digital transmission system designed and developed by A TL T elecom Ltd. in Cardif f. It is intended for operation on 2-wire local telephone network cir cuits, such as those meeting BT EPS-9 (2-Wire). It will operate satisfactorily on unloaded lines ha[...]

AM64/128A User Manual System Overview 8 The interface circuit performs a number of functions : it converts between the user data fr om the appropriate interface and the 64kbps or 128kbps, which is transmitted down the line; it links the contr ol circuit to the contr ol channel; it interfaces the control cir cuit to the control lines of the data por[...]

Installation AM64/128A User Manual 9 4. INST ALLA TION This chapter describes the basic steps that are r equir ed to set up a system involving the Baseband Modems (BBM's). There ar e two basic systems that will be considered: (1) BBM connected to BBM (2) BBM connected to Line Card When considering the installation general pointers to the confi[...]

AM64/128A User Manual Installation 10 Set the line rate (section 5.7.2) as requir ed at both ends, and set the user data rate up on the master (section 5.5). When the line is connected the F AUL T LED should go out. The interface details and synchronous or asynchr onous working should now be configured at both ends. This is done using the option me[...]

Installation AM64/128A User Manual 11 4.2 BBM to Line Car d Link Power up the BBM as described previously , and set the modem to slave mode. Set the line rate as requir ed, and connect the line cord. Consult the line card handbook to set up the user data rate. The modem should automatically pr ogram to this rate. There will be an ‘options enable?[...]

Menu Operation AM64/128A User Manual 12 5. MENU OPERA TION 5.1 Front Panel Featur es The Baseband Modem has an uncluttered and easy to understand fr ont panel. It has a liquid crystal display (LCD), 5 LED’ s, and 6 non-locking keys. With the 16 character alphanumeric, dot-matrix liquid crystal display it is possible to describe most of the functi[...]

AM64/128A User Manual Fr ont Panel Operation 13 5.2 Fr ont Panel Operation The LCD will display one of five menus at any one time, these menus are: 1. ST A TUS (Prompt is S>) 2. TEST (Prompt is T>) 3. RA TE (Prompt is R>) 4. OPTION (Prompt is O>) 5. CONFIG (Prompt is C>) In normal circumstances, the fr ont panel LCD will display a St[...]

Status Menu AM64/128A User Manual 14 5.3 Status Menu The status menu is read only , which means the select button has no effect. It pr ovides the following data: (1) Overall status (2) Alarm messages (3) User data rate (4) Line rate (5) Interface status (6) Operating mode 5.3.1 Over all Status The possible messages for this item in priority order ,[...]

AM64/128A User Manual Alarm Status 15 5.3.2 Alarm Status The possible messages for this item are: S > No Alarm S > No Signal S > Receiving AIS S > No Alignment The S > No Signal display indicates that the transmission system cannot find a signal to lock on to. Possible causes are: (a) Br oken or defective line (b) Both ends master , [...]

Status Menu AM64/128A User Manual 16 5.3.3 User Rate This item displays the user rate in current use. A complete list is given in section 5.5 - Rate Menu. For example: S > 48K 10 5.3.4 Line Rate This has to be set locally to the BBM via the front panel and cannot be downloaded fr om the Master unit. This displays the line rate in use: If the hig[...]

AM64/128A User Manual Menu Operation - Status Menu 17 5.3.6 Operating Mode The BBM is capable of operating in two basic modes: S > Link Mode S > Network Mode For a BBM to BBM link this display should read Link Mode. If however a Line Car d is used instead of a master BBM, then the display should read Network Mode. The essential dif ferences o[...]

Menu Operation - T est Menu AM64/128A User Manual 18 5.4 T est Menu 1. Local loop 2. Loop back 3. Remote loop 4. Binary pattern 5. Data error test 6. In service error test 7. Lamp test 8. Self T est 9. Comms channel loop 5.4.1 Local loop This is a loop applied within the local BBM. It loops data back to the DTE from a point as close to the interfac[...]

AM64/128A User Manual T est Menu 19 With a G.703 Interface fitted, the application of a local loop will cause G.703 data to be looped back to the G.703 network at the G.703 interface (known as a Loop B / LCB loop on the G.703 linecard and standalone units) as shown in figure 5.4.1.2 below . 5.4.1.2 Local loop from DTE T o apply a local loop in this[...]

T est Menu AM64/128A User Manual 20 With a G.703 interface fitted, the application of a loopback will apply a loopback to line at the remote slave unit (known as an L TU loop on the G.703 linecard and standalone units). Note : It is not possible to “Hardwir e” a G.703 loop at the G.703 interface connector . 5.4.3. Remote Loop Remote loop involv[...]

AM64/128A User Manual T est Menu 21 5.4.3.2 Remote loop from DTE When the BBM receives an ART pattern (00110011) from the DTE (in X.21), or when cir cuit 140 is active (in X.21bis) the loopback is applied on the remote BBM similarly to the above. T o apply a remote loop in this fashion refer to your DTE handbook for details. The BBM can be in any m[...]

T est Menu AM64/128A User Manual 22 5.4.5 Data T est 5.4.5.1 Overview This mode allows the user to send a binary 0's pattern to the remote BBM and monitor the received data stream for err ors Note : every binary 1 received is tr eated as a single error . The number of bits received in error is displayed on the LCD. The test time elapsed can al[...]

AM64/128A User Manual T est Menu 23 The Data T est can be used to test the performance of a link (0 or 1 patterns on the two wire line are all AMI encoded and framed as described in section 3). Note: Apply any loops requir ed before entering Data T est Mode. Enter the test menu and scroll to : T> Data T est then press SELECT . There ar e four di[...]

T est Menu AM64/128A User Manual 24 2/ Pattern display The pattern display usually shows Injecting 0s Pressing SELECT will cause binary 1s to be injected (e.g. for loop verification): Injecting 1s This pattern will continue to be injected until the SELECT key is pressed again, (or the mode is exited). 3/ Transparency display The T ransparency optio[...]

AM64/128A User Manual T est Menu 25 5.4.6 In Service T est 5.4.6.1 Overview This mode allows the error performance of the line to be monitor ed, without interrupting data traffic. This works by monitoring the accuracy of some of the overhead bits that make up the transmission frame structure. As the data channel itself is not monitor ed, the figure[...]

T est Menu AM64/128A User Manual 26 5.4.7 Lamp T est This facility is used to check the LED’ s and the LCD display . T o activate the test choose the item T > Lamp T est Pressing SELECT will cause a complete line of blocks to show on the LCD. Simultaneously all the LED's should light up, for about 3 seconds. On completion, the LCD will re[...]

AM64/128A User Manual T est Menu 27 However , the usage of the EEPROM (Blocks Used) is still displayed for information. For example: 000 means that the first block is in use and that there ar e 254 empty blocks. 254 means that the last block is being used and the chip is nearly full. The failure messages have the following implications: 1. EPROM Fa[...]

Menu Operation - Rate Menu AM64/128A User Manual 28 5.5 Rate Menu The rate menu is only accessible in master mode. In slave mode the user rate is dictated by the master BBM. The rate can then only be viewed in the status menu. This menu consists of a number of data rates from which one can be selected, except for 128k line rate, where 128k data rat[...]

AM64/128A User Manual Rate Menu 29 The Rate menu operates slightly differ ent when 64k mode is activated. It is described more fully in the Configuration Menu (Section 5.7). Briefly , this mode involves the master BBM set to 64K + BT , and the slave BBM set to some other rate. As far as the rate menu is concerned there are now two separate rates to[...]

Menu Operation - Option Menu AM64/128A User Manual 30 5.6 Option Menu This menu displays the type of DTE interface currently fitted in the BBM. The AM64/128A automatically “reads” which interface type is fitted on power up, and pr ograms certain options accor dingly . The first two display options are r ead only . These display the following in[...]

AM64/128A User Manual Menu Operation - Option Menu 31 (3) O > 107 Normal Press SELECT : O > 107=108/1 This allows control line 107 to follow contr ol line 108/1 independent of other factors. (4) O > 108/1 Normal Pr ess SELECT O > 108/1 Set On This option holds the control line 108/1 ON internally . There ar e three options for the X.21b[...]

Menu Operation - Option Menu AM64/128A User Manual 32 5.6.6 Character Length Scrolling down further gives the display: O > Char Len: 8 Pressing SELECT changes the length between the four options, 8, 9, 10 and 11 bits. The character length sets the total character length including one start bit, one stop bit and possible parity bit. Pressing SELE[...]

AM64/128A User Manual Menu Operation - Configuration Menu 33 5.7 Configuration Menu This menu contains the items that are used in the initial configuration of the BBM. Once set up they ar e usually left unchanged for normal BBM operation. All of the configuration parameters are stor ed in non- volatile memory and are r estored each time the BBM is [...]

Configuration Menu AM64/128A User Manual 34 5.7.3 X.21 Loop Control This facility is designed for when a pair of BBM’ s are used as an extension to another BBM link. The concept is shown below . Figure 5.7.3 BBM’ s A and B form part of a conventional link. However in this example, instead of a DTE being connected to BBM B another link is starte[...]

AM64/128A User Manual Configuration Menu 35 5.7.4.1 Synchronisation T ype (for software version V1.3 and above) With these later versions of software, there ar e three possible options depending upon which interface is fitted, whether Master or Slave mode is selected, and the rate selected. Option 1 - C > Ext Byte Clk This option is shown when t[...]

Configuration Menu AM64/128A User Manual 36 5.7.5 64k Mode This mode is designed to be used in association with the X.50 framing patterns. When the mode is selected the master BBM is set to 64k and the slave is (usually) set to 48k X.50. This allows the master BBM to become transparent to the X.50 framing structur e, allowing it to be processed by [...]

AM64/128A User Manual Glossary 37 GLOSSAR Y OF TERMS AIS Alarm Indication Signal. AL T Automatic Local T est. - Patter n sent to apply a local loop in the DCE. AMI Alternate Mark Inversion. - Code used for line transmission. ART Automatic Remote T est. - Patter n sent to apply a loopback on the remote modem. BBM Baseband Modem. BT Byte Timing. - Sy[...]

Glossary AM64/128A User Manual 38 V .24 CCITT specification. List of definitions for inter change circuits between DTE and DCE. V .28 CCITT specification. Electrical characteristics for unbalanced double-curr ent interchange circuits. (V .28 Interchange cir cuits defined in V .24) V .35 CCITT specification. Data transmission at 48kbit/s using 60-10[...]

AM64/128A User Manual Specifications 39 GENERAL SPECIFICA TIONS T ransmission system uses DSP techniques involving echo cancellation and adaptive decision feedback equalisation. The system is intended for use on 2-wire unconditioned copper wir e (BT EPS-9 type circuits). Power output selectable 0dBm or 10dBm. Line code is AMI with embedded synch pa[...]

AM64/128A User Manual Appendix A - Interface Connections A-1 APPENDIX A - Interface Pin Connections 25 W ay D - type X.21 bis (V .24 / V .28*) Connector pin allocation *V .28 defines the electrical characteristics of the circuits of a V .24 interface. Note: Circuit 105 Request to send may have to be set in the Options Menu - see Appendix F (T roubl[...]

Appendix A - Interface Connections AM64/128A User Manual A-2 V .35 (MRAC) Connector Pin allocation Note: Circuit 108/1 is not available on the connector as an interface line but is softwar e clamped in the ON state. Pin Unbal B C D E F N L NN* Description Common Return T ransmitted Data Received Data Request to Send Ready for Sending Data Set Ready[...]

AM64/128A User Manual Appendix A - Interface Connections A-3 25 W ay D-type RS-530 Connector pin allocation *Standards dictate that the contr ol circuit 107 may be implemented as a balanced cir cuit (using both A and B wires) or as an unbalanced single ended cir cuit. In the AM64/128A, circuit 105 is implemented as a balanced cir cuit and 106,107,1[...]

Appendix B – Internal Link Settings AM64/128A User Manual A-4 APPENDIX B – Inter nal Link Settings[...]

AM64/128A User Manual A-5 The function of the links is as follows: J1 T ransmission disable This link is always left in position 1-2 J11 W atch dog enable This link is always left in position 1-2 J21 This connects the supply earth to the circuit ground in position 1-3 The circuit gr ound is floating in position 1-2 W ARNING Only authorised personne[...]

AM64/128A User Manual Appendix B – Internal Link Settings A-6 Interface Modules X.21 Interface Module: J1 - X.21 T (T ransmit data) Circuit T ermination – This link connects a 120 ohm load resistor acr oss the T circuit position 1-3. This helps maintain signal rise times and minimises r eflections at rates greater than 9.6 kbps over long lines.[...]

AM 64/128A User Manual Appendix B – Internal Link Settings A-7 Interface Modules: RS530 Interface Module: J1 – V36 and RS530 Circuit 103 (T ransmit data) Circuit T ermination – This link connects a 120 ohm load resistor acr oss the 103 cir cuit in position 1-3. This helps maintain signal rise times and minimises r eflections at greater than 9[...]

Appendix C - In Service T est AM64/128A User Manual A-8 APPENDIX C - In Service T est BACKGROUND INFORMA TION The information passing between master and slave BBM’ s comprises of user data and control data; the latter is used for controlling and supervising the operation of the transmission system. In or der that these components can be separated[...]

AM64/128A User Manual Appendix C - In Service T est A-9 It must be remember ed that this err or count is unidir ectional only . There can be no looping of the envelope alignment bits. This fact can be used to advantage in determining the location of noise on a link. Consider an example where two BBM’ s are connected together . BBM1 indicates a hi[...]

Appendix D - Approvals AM64/128A User Manual A-10 APPENDIX D - Appr ovals L VD - Safety Statements: Power Rating Information - AC Source: 1. V oltage Range: 230/120V ac. 2. Current Range 40mA at 230V and 85mA at 120V . 3. Frequency Range 50/60Hz. Safety Instructions: 1. The apparatus must be installed and maintained by COMPETENT SERVICE PERSONNEL. [...]

Appendix E - Private digital circuits AM64/128A User Manual A-12 APPENDIX E Use on X.21/X.21bis digital circuits - External Timing Configuration The details in this appendix relate to the arrangement shown in figur e E.1. The main differ ence between this arrangement and the conventional link is the need for a special interface cable which joins th[...]

AM64/128A User Manual Appendix E - Private digital circuits A-13 2. X.21 byte timing cable - (15 way to 15 way D type plugs). 3. V .24 / V .28 bit timing cable - (25 way to 25 way D type plugs). 4. V .35 bit timing cable - (34 way to 34 way MRAC plugs). CCITT circuit T- A T- B R-A R-B B-A B-B I-A I-B C-A C-B GND CCITT circuit R-A R-B T- A T- B SEXT[...]

Appendix E - Private digital circuits AM64/128A User Manual A-14 5. X.21 bis V .36 bit timing cable - (37 way to 37 way D type plugs). * In some cases it may be necessary to connect this line to GND (102) at the receiver end of the link dependant upon the implementation of the interface control lines - balanced or unbalanced. 6. RS530 bit timing ca[...]

AM64/128A User Manual Appendix F - T roubleshooting A-15 Appendix F - T r oubleshooting Please check the following points if problems ar e encountered when setting up a BBM link. 1. Ensure the modem is being used on unconditioned copper twisted pair wir e. 2. Check one modem is set to Master and the other modem is set to Slave. 3. Check line rate i[...]

Appendix F - T roubleshooting AM64/128A User Manual A-16 In some environments, the external timing input (SEXT on X.21 or circuits 113 on the X.21 bis interfaces) of an AM64/128A set in Master Mode may become sensitive to external coupled noise. This may have the effect of pulling the modem’ s VCO (inter nal oscillator) off to one side and causin[...]

AM64/128A User Manual[...]