Equipment information

Wandel & Goltermann PCM-4 Communications Test Set
Manufacturer:
Model:
PCM-4
Date:
1996
Category:
Group:
Description:
PCM Channel Measuring Set

Information

Rising costs have forced telecoms authorities and industrial users to seek economical solutions to test and measurement problems. The PCM-4, equally suitable for manual or remote-controlled operation, has all the functions needed for a complete coder/decoder test set, representing a cost-effective answer to this particular test requirement. All measurements conform to the relevant CCITT standards. COMPACT CONSTRUCTION The PCM-4 covers the functions of several different test sets, making measurements easier and reducing the number of connections required. A further plus is the reduced transport cost. Four main parts make up the signal Generator and receiver unit: « an analog signal Generator for sine-, multitone-, and "noise" signals; % a digital signal Generator which provides various signals via a 64 kbit/s Interface or inserts them into standard PCM frames; 9 an analog receiver for rapid wideband measurements in the telephone channel or for out-of- band measurements up to 128 kHz and for selective ineasurements at particular frequencies; • a digital receiver for evaluating the digital words in both speech and signalling channels, the signal status being indicated by LEDs. These units, together with a processor system comprising several microprocessors, make a wide range of measurements possible. These are summarised in the table at the end of this introduction. SIMPLE OPERATION The use of a VOU and three operator levels make working with the PCH-4 very easy: • All the different types of measurement are contained in two lists, list A for the measurements which are often used, and list B for the less common ones. To select a measurement, the measurement number is entered. A list of parameters, such as signal type, frequencies and signal level, is shown on the screen. Once you nave selected one of these parameters, the VDU shows all the relevant parameters and tolerance masks for the selected measurement. The PCH-4 is ready to make the measurement. The framework for the various measurements, i.e. the parameters, are set to standard values when the instrument is switched on for the first time. These parameters can be altered if required, but are reset to the standard values if /GENRL. RESET/ is pressed, or if the backup batteries become discharged before the instrument is switched on again. • If you need to alter the parameters, press /GENRL. PARAM./. This causes a menu to appear on the VDU} showing a number of parameter lists. Entering the list number causes the selected list to be displayed. Parameter changes are made by selecting one from a number of possibilities or by entering a new value. The PCH-4 displays error messages which warn you if you have selected a combination of parameters which is illegal or has no meaning. The new values are stored and used for all subsequent measurements and are not erased when the instrument is switched off and on again. • Once you are familiar with the instrument and its operation, it is also possible to make changes in the individual measurement inodes to suit requirements. This is done using the /VAR. MODE/ key. This allows different reference values or integration times to be selected, for example. These alterations are erased when a new measurement mode is chosen or if the PCM-4 is switched off. MINIMAL MEASUREMENT ERROR One of the most important features of the PCM-4 is its accuracy. This is of particular importance when making half-channel (analog-digital or digital-analog) measurements, as the allowable error is half that permitted for full-channel measurements. The two descriptions which follow may serve to explain how it is possible to obtain such a small measurement error: s All actual signal processing is at the digital level. Received analog signals are sampled and digitised and a digital Filter is used for weighting the resultant digital signal. The tolerances for such filters can be calculated, and are independent of temperature or ageing effects. In this way, the analog filter, which is a major source of errors, is dispensed with. « Only one highly accurate attenuator is used in the PCM-4. This is a transformer-type attenuator, the accuracy of which is solely determined by the turns ratios. All of the remaining attenuators are tapped resistor chains. When the instrument is calibrated, first the receiver attenuator and then the Generator attenuator are compared with the transformer attenuator. Any deviations are noted for each attenuator stage, these being stored as correction factors which are taken into account for each subsequent setting of the attenuators. CLEAR DISPLAY OF RESULTS All results are displayed clearly on the VDU, You have a choice between: - graphical display versus the ‘'running" or X-axis parameter, or - numerical display in tabular form. If you want to keep a record of the results, a video plotter, graphics plotter or printer can be used. For the video plotter or graphics plotter, an IEC 625 Interface is required. The following can be output on the printer; - the complete contents of the measured value memory on manual command - each complete result automatically, or - measured values which are outside given tolerance limits. If required, the limit value can be printed together with each measured value. RAPID AUTOMATIC TESTING Forty complete instrument settings (setups) can be stored and recalled as required. The PCM-4 can automatically call up and execute all the setups in address order. When coupled with a printer programmed to print out values which are out of tolerance, the PCM-4 fortns a powerful automatic Test Set. The use of a desk-top computer and IEC 625 bus network opens up further possibilities, for example, the computer can be used to call up and start preset setups, only the running parameter (e.g. frequency) being changed between measurements. As the data transfer and the measurements overlap, measurements are not interrupted when new settings are made. If a full-scale computer is used, the PCM-4 becomes more than just a test set; here are two examples: • Statistical evaluation of the results allow test engineers to determine the accuracy of error predictions made during development; • Long-term measurements on transmission systems can be used to determine the effects of ageing on the various component parts of the network. In this way, trends can be recognised, so that threatened failures or out-of-tolerance performance of a given module can be seen easily.

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User Manual
Manual Type:
User Manual
Pages:
496
Size:
17.14 Mbytes (17968772 Bytes)
Language:
english
Revision:
55/95.07, AK
Manual-ID:
BN 0984/00.82
Date:
1996 01 01
Quality:
Scanned document, all readable.
Upload date:
2017 01 22
MD5:
22398a7344663e2dbd049b757d23d253
Downloads:
828

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Operating Manual INTRODUCTION J SPECIFICATIONS ... 1-1 ANALOG SIGNAL Generator 1.1 Generator output ... 1-1 1.2 Generator signals ... 1-1 1.3 Generator level ... 1-3 1.4 Other outputs ... . 1 -3 ANALOG RECEIVER 1.5 Receiver input ... 1-4 1.6 Receive level ., ... ■ ... 1-4 1. 7 Receive f i Iters ... 1-5 DIGITAL SIGNAL Generator 1.6 PCM frame structure ... 1-6' 1.9 Generator outputs, digital s igna 1 & c lock* ... i-6 1.10 Operating modes and clock generation ... 1-7 1.11 Digital words in time slots 0 and 16 ... 1-8 1.12 Digital words in telephone channels ... 1-9 1.13 Generator signals ... 1 - i0 1.14 Test facilities and error injection ... 1-13 1.15 Trigger outputs ... 1-13 DIGITAL SIGNAL RECEIVER 1.16 PCM frajise structure ... 1-13 1.17 Digital signal inputs ... 1-14 1.18 Evaluation of digital words in telephone and signalling channels ... 1-15 1.19 Analog measurements on telephone channels ... 1-15 1.20 Receive f i Iters ... 1-15 1.21 Analog decoder output [37] ... 1-15 1. 22 Error measurements ... , , , ... 1-15 1.23 Evaluation and indication of the digital words within a frame ... 1-16 1.24 Error counts on frame and mu It iframe a 1ignment s igna Is ... 1-16 1.25 Parallel outputs [62] (on back panel) ... 1-16 1.26 S ignal 1 ing distort ion measurements ... 1-17 1.27 Error I imits ... 1-17 1. 27 Measurement times ... 1-25 OPTIONS 1.29 Codirectional 64 kbit/s input, BN 384/00.01 ... 1-26 1.30 Codirectional 64 kbit/s output, BN 384/00.02 ... 1-26 1.31 64 kbit/s contradirectional input BN 384/00.03 ... 1-27 1.32 64 kbit/s contradirect ional output BN 984/00,04 ... 1-28 1.33 64 kbit/s TTL serial input, 8N 984/00.05 ... 1-28 1.34 64 kbit/s TTL serial output, 6N 984/00.06 ... 1-29 1.35 64 kbit/s TTL parallel input, BN 984/00,07 ... 1-30 1.36 64 kbit/s TTL paral lei output, 8N 384/00.08 ... 1-30 1.37 64 kbit/s V.ll Interface BN 984/00.09 ... 1-31 1.38 Return loss and longitudinal conversion transfer loss bridge ... 1-32 1.39 Remote control via < I EC 625>/IEEE 488 Interface bus ... 1-32 1.40 V ideo output ... 1-33 1.41 General specifications ... ,1-33 1.42 Accessories ... 1-35 1.43 Ordering information ... 1-36 2 GENERAL INFORMATION FOR THE USER ... 2-1 2.1 Important safety instructions ... 2-1 2.2 Ventilation and rack mounting ... ... 2-2 2.3 Power supply, fuses ... 2-3 2 .4 Switch-on ... 2-4 Z. 5 Disposal of bui It - in batteries ... 2-6 3 OPERATING INSTRUCTIONS ... 3-1 3.1 Front panel controls and connectors ... 3-1 3.2 Back panel inputs and outputs ... 3-12 3.3 Operating procedure for the PCM-4 ... 3-17 3.4 Storage and recall of instrument settings ... 3-19 3.5 Graphic display of results ... 3-25 3.6 General parameters ... 3-32 3.7 MODE LIST A measurements ... 3-79 3.8 MODE LIST B measurements ... 3-112 3.9 VAR. MODE ... 3-134 4 REMOTE CONTROL ... 4-1 4.1 Introduct ion ... 4-1 4.2 Instrument setup ... 4-1 4.3 Programming ... 4-13 4 . 4 Program words ... ... 4-37 4.5 Example programs ... 4-69 i 5 OPTIONS, Accessories ... 5-1 5.1 64 kbit/s interfaces ... 5-1 5.2 Return loss and longitudinal conversion loss measuring bridge ... 5-21 5.3 OC loop-holding circuit GH-1, 8N 984/00.12 ... 5-22 5.4 DC decoupling unit PCMZ-4, BN 984/00.13 ... 5-23 5.5 120 kHz low-pass f i Iter BN 0984/00.14 ... 5-25 APPENDIX A: INSTRUMENT DESIGN ... A-l APPENDIX B ... B-l B.l Error signals on self test and calibration ... B-l B. 2 PCM-4 f unct ion check ... B-4 APPENDIX C: OPTIONS, ACCESSORIES, MAINTENANCE ... C-l C.l Instrument designation ... C-l C.2 Accessory compartment ... C-l C.3 Changing the Versacon inserts ... C-2 C.4 Changing the fuse ... C-2 C.5 Data back-up battery ... C-3 C.6 Cleaning the instrument ... C-3 C.7 Removing batteries ... C-4 APPENDIX D: USER-SPECIFIED TOLERANCE MASKS ... : ... D-l 0.1 Tolerance mask structure in the PCM-4 ... D-l D.2 How to complete forms 1 to 4 ... D-4 0.3 fitting the EPROM with user-specified tolerance masks ... B-22

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User Manual
Manual Type:
User Manual
Pages:
36
Size:
679.78 Kbytes (696091 Bytes)
Language:
english
Revision:
Edition 2
Manual-ID:
BN 0934/00.89
Date:
1989 01 01
Quality:
Scanned document, all readable.
Upload date:
2017 01 22
MD5:
62b836eae91041f1296359c3a3a3845f
Downloads:
517

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Shortform operating instructions Contents 1 Self test, calibration ... ... 3 1.1 Software status display ... ... 3 2 Main parameter menus ... ... 4 3 Parameter list 0 ... ... 6 4 Parameter list 1 ... . . . 7 4.1 Configuring the Interface ... . ... 7 4.2 Digital loop circuits ... o 5 Parameter fist 2 ... ... 12 5.1 Frame selection ... ... 12 5.2 CRC ... ... 12: 6 User-specified tolerance masks ... ... 13 7 Results display ... ... 14 7.1 Numerical display ... ... V- 7.2 Graphical display ... ... ie 8 Setup memory ... . ' ... 1£ 8.1 Store ... ... 18 8.2 Erase setup ... ' ... ... 16 8.3 Erase all setups ... ... 18 8.4 Recall ... ... IS 8.5 Adding a setup to a sequence ... ... 2C 8.6 Removing a setup from a sequence ... ... 21 8.7 Clearing a sequence ... ... 21 9 UsingtbePCM-4withtheMU-30 ... ... 22 9.1 4 wire circuit measurements ... ... 22 9.2 2wire circuit measurements ... ... 24 9.3 Digital circuit measurements ... ... 26 10 Controls and connections ... ... 23 10.1 Front panel, numerical order ... ... 28 10.2 Sackpanel,numericatorder ... ... 29 10.3 Front pane!, alphabetical order ... ... 30 10.4 Sackpanel, alphabetical order ... ... . 32

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