manualshive.com logo in svg

Data General 6020 Series, Technical Manual

Share
Download
Data General 6020 Series Technical Manual Download Page 1

Summary of Contents for 6020 Series

Page 1: ......

Page 2: ...aterials contained herein and shall not be responsible for any damages including consequential caused by reliance on the materials presented including but not limited to typographical or arithmetic er...

Page 3: ...6020 SERIES TAPE TRANSPORT OVERVIEW MECHANICAL ASSEMBLIES TRANSPORT CONTROL LOGIC ANALOG AND SERVO FUNCTIONS POWER SUPPLY AND DISTRIBUTION APPENDICES DataGeneral El 11111 IDI ml...

Page 4: ...This page intentionally left blank...

Page 5: ...Signal Names REFERENCE DOCUMENTS MECHANICAL ASSEMBLIES INTRODUCTION INTERNAL WIRING AND CABLES Cable Connectors Vacuum Blower Assembly POWER SUPPLY VACUUM COLUMNS AND MANIFOLDS CAPSTAN TACHOMETER ASS...

Page 6: ...ORS CONSOLE Flowchart Conventions Power Up Sequence Load Sequence Unload and Unwind Sequence Unload Unwind Rewind Sequence On Line Sequence Reset Sequence CONTROL SIGNALS EXCHANGED WITH THE TAPE CONTR...

Page 7: ...Characters and Bytes Records or Blocks DATA WRITING PATH Data Receivers and Write Drivers Deskew Register Static Deskew Write Protection Write Current Ground Isolation Write Disabling on Failing Powe...

Page 8: ...ANALOG SWITCHES N Channel Analog Switch P Channel Analog Switch SERVO DISABLING INTERLOCKS VACUUM COLUMN TAPE BUFFER SERVO SYSTEM Vacuum Transducer Servo Preamplifiers Summing Amplifier and Biasing Ci...

Page 9: ...SPECIFICATION OVERVIEW FUSES REMOTE ENERGIZER CONSTANT VOLTAGE TRANSFORMER DC GROUNDS ISOLATION VOLTAGE REGULATORS 5 Volt Regulator 10 6 Volt Regulators 12 Volt and 5 5 Volt Regulators OVER VOLTAGE PR...

Page 10: ...RINTED CIRCUIT BOARDS AIR FLOW AND VENTILATION IN THE TRANSPORT SUPPLY VOLTAGES CONFIGURATION Fuses Remote Energizer DC Grounds Isolation RECTIFIERS DC BREAKER AND NON REGULATED RUSSES REGULATORS Swit...

Page 11: ...erating A system diagram of the transport is shown on the next page The transport contains four principal systems which work independently to provide reliable gentle tape handling They are The operato...

Page 12: ...ced in whole or in pul wilhout DGC s prior written ppronl nor be implied lo gr int ny lkense to m iike use or self equipment m nufKtured in ilCcord nce herewith 6020TRANSPORT TO FROM TRANSPORT CONTROL...

Page 13: ...ing the reel motor in the correct direction adding or removing tape from the column to achieve the right position There are two reel servos as shown along the left side of the drawing Each servo opera...

Page 14: ...nding on how it is defined To distinguish between the two types of signals a naming convention has been adopted which defines the relationship between the logical value and the electrical level of a s...

Page 15: ...A 008 0004 A 008 0020 A 008 0020 A 008 0020 A 008 0020 A 008 00201 D 01 0 0001 0 001 0005 SERVOS DATA 0 001 00051 HANDLING AND I 0 016 0001 CONTROL LOGIC D 016 0001 0 001 0011 TRANSPORT 0 001 00111 P...

Page 16: ...This page intentionally left blank I 6...

Page 17: ...n the main casting Two printed circuit boards are mounted on the back of this casting which swings open frontwards to provide easy accessibility to all of the transport parts The mechanical assemblies...

Page 18: ...cing the main vacuum manifold at a negative pressure approximately 30 inches of water The flap valve provides quick release of the vacuum system when the blower is shut down by closing the blower s ou...

Page 19: ...r and fan The ferro resonant power transformer converts the ac line voltage to several coarsely regulated voltages for the power supply The rectifier and filter pan converts the ac outputs from the tr...

Page 20: ...the slower response of the tape reels They also maintain the tape at a constant tension The organization of the vacuum columns manifolds a nd the buffers failsafe switches is shown in the illustration...

Page 21: ...p draws vacuum in both columns through the main vacuum manifold This pulls a loop of tape into both columns The tape loop in a column divides the row of sensing holes into two parts The holes between...

Page 22: ...LOCATIONS CAPSTAN MOTOR DG 01311 TACHOMETER II 6 REEL MOTORS AND HUB ASSEMBLIES The reel motors spin the tape reels in response to servo commands so that the tape remains balanced in each vacuum colum...

Page 23: ...event scoring of the transcription head use only soft cotton applicators against its surface Paper Towels in general have much too abrasive a surface and can damage both the head and eventually any ta...

Page 24: ...e vacuum columns The head guides are two ceramic washers mounted on chrome plated posts over which the tape passes The upper washer away from the casting surface is fixed in position and is in contact...

Page 25: ...gulator and power control circuits as well as the power amplifiers that drive the reel motors The largest circuit board mounts vertically on two brackets attached to the casting and measures approxima...

Page 26: ...itten approv al nor be implied to grant any license to make use or sell equipment m anufactured in accordance herewith AIR FLOW AND VENTILATION IN THE TRANSPORT One compact fan provides ventilation fo...

Page 27: ...hen an operator mounts a reel of tape on the transport and presses Load a distinct series of circuit level events take place to load the vacuum columns while several tests verify that the sequence is...

Page 28: ...efers to the engineering schematic and revision level from which the flowchart was constructed 2 The statement contained in any box of the flowchart describes a logic event or decision 3 Where appropr...

Page 29: ...r in pilrl without DCiC s prior written ilpproval nor be implied lo gr int ilny license to milke use or sell equipment m inufilctured in ilccordilnce herewith LOAD NO 556 188 VAC 20 H REFERENCE PRINTS...

Page 30: ...um columns are not operating Releasing the switch causes the unwind operation to stop Ill 4 Unload When the unload sequence is initiated the transport rewinds tape to the loadpoint if it is not alread...

Page 31: ...rewith UNLOAD DG 01222 FAILSAFE IS ACTIVE PRESS UNLOAD 508 C7 ALLOK H YES YES 508 C6 UNLOAD FF 1 H 508 C7 BOT H NO 508 C7 BOT L GOTO REWIND BOT H RETURN FROM REWIND SHUTDOWN TAPE BUFFERS RELEASE VACUU...

Page 32: ...ff line and not under program or computer control when the transport is On Line and when a BOT reflector is not located during the forward search of the load sequence In all cases the rewind sequence...

Page 33: ...Unit Select switch on the operators panel NOTE Indeterminate logical and status conditions can be encountered by the computer software if more than one transport in a tape subsystem is assigned the sa...

Page 34: ...between the tape transport and the tape subsystem controller when the unit is On Line The signal RUN initiates tape motion forward or LOCATION AT THE BACK PANEL SIGNAL NAME OF A DATA GENERAL COMPUTER...

Page 35: ...and formatting within a data record The timing circuits are divided between the controller and the transport so that transports with differing tape speeds data densities and number of tracks can be c...

Page 36: ...he controller asserts the signal SEND CLOCK to first clear and then enable the transport counter at the start and conclusion of each tape operation This also initializes the overflow counter with the...

Page 37: ...nnel magnetic tape equipment operating in the low to medium density range For data densities below about 1000 bits per inch bpi NRZI coding provides highly reliable data storage and retrieval yet requ...

Page 38: ...o the opposite direction This is because the direction of the magnetic field across the gap depends on the direction ofcurrent in the magnetizing coil CURRENT REVERSED L DG 01264 IV 2 The recording su...

Page 39: ...d whenever a flux reversal recorded on tape crosses the gap The amplified pulses are interpreted as the binary value of 1 It is possible to use the same electromagnet for both reading and writing by s...

Page 40: ...ch character therefore appears across the width ofthe tape Characters and Bytes A character is generally composed of a number ofdata bits and one parity bit The data bits in a character are collective...

Page 41: ...er is first turned on at the transport the current drivers are initialized to a specific current direction even though the windings are not actually energized until a writing operation occurs This ini...

Page 42: ...ost reels of computer grade tape and a plastic ring called an enabling ring can be inserted into that groove When the ring is removed the transport is write protected and data cannot be written The wr...

Page 43: ...ntial amplifier and then a common emitter transistor amplifier A test point at the transistor emitter in each read chain provides for convenient gain monitoring and adjustment Correct adjustment of th...

Page 44: ...on tape Data Register and Line Drivers When a bit value of 1 is detected in any track during reading writing or spacing the value 1 is loaded into the appropriate cell of the transport data register T...

Page 45: ...e that relate to most digital logic circuits These analog systems include the capstan servo system and two vacuum column tape reel servos There are two independent reel systems one for each column and...

Page 46: ...what is desired An actuator or driver which changes the output For instance the capstan is controlled by a servo The simplified block drawing below shows how the four basic elements of a servo work to...

Page 47: ...extremely high and its output signal will quickly reach a maximum saturate when there is merely a few millivolts or so difference between the input terminals and Yet the amplifier can be connected in...

Page 48: ...nt of the values of input series resistors In the scalar amplifier the input resistance and its component tolerance directly affect the output signal This characteristic makes the follower useful as a...

Page 49: ...ut signal is a square wave the output of the integrator looks like this INTEGRATOR WAVEFORMS Vin D D t D D D Vout t 7 DG 01233 V 5 Summing Amplifier The analog building blocks may have several inputs...

Page 50: ...al electrical connection VIRTUAL GROUND IN DG 01236 THIS PROBE SEES NO SIGNAL OUT THESE PROBES SEE THE INPUT AND OUTPUT VOLTAGE SIGNALS RESPECTIVELY 2 The output signal of an operational amplifier can...

Page 51: ...to approach ideal operation only over a certain range ofsignal conditions Compensation techniques are available to prevent feedback instabilities from originating in either of these two areas Externa...

Page 52: ...inals allow a compensating network or component to be added that optimizes the operation of the amplifier for the configuration in which it is being used However for the analog building blocks discuss...

Page 53: ...switch s gate to track with its source The tracking resistor forces the source gate voltage to remain at precisely zero volts whenever the gate s driving circuit is not forcing the switch fully off _...

Page 54: ...ailure they affect an orderly shut down of the systems in a manner that presents the least possible damage to the magnetic tape If there is an incorrect voltage in any of the de power supplies an ac p...

Page 55: ...art of the servo disabling system Four of the switches close at a vacuum of ten inches water these switches detect excursion ofthe tape past the inner or outer extremities of the two vacuum columns A...

Page 56: ...ifferent subassemblies the diagram also shows where the servo elements are located inside the transport The description that follows briefly summarizes the operation ofthe reel servos Each major eleme...

Page 57: ...pe moves up and down over the sensing holes inside the column The illu Stration at right shows how this is done A small spring loaded pneumatic piston is connected through a short tube to the manifold...

Page 58: ...is badly misaligned When the column adjustment is correct the error signal measured at the output test pad of a preamplifier will remain less than a volt plus or minus while the tape is at equilibriu...

Page 59: ...ier stage in the two reel servo systems are nearly identical Each amplifier contains three gain selectors which change the degree of amplification performed on the signal from the first amplifier in r...

Page 60: ...reduces the amount of heat generated in the reel motors the power amplifier and the power supply and is a principal reason why no external source of ventilation is required to cool the transport cast...

Page 61: ...t i ansients from overloading the servo The glitch filter is simply two diodes connected in parallel with opposite polarity as shown below GLITCH FILTER FROM PREAMP DG 01254 TO DIFFERENTIATOR AMPL If...

Page 62: ...OAD TAPE TURNS DG 01323 Q20FF WHEN INPUT ISLOW f 1 SUMMING AMPL V 18 During the load sequence LOAD TAPE and SPIN TAKE UP assert for 400 milliseconds shortly after the vacuum blower is energized Both r...

Page 63: ...le between a summing amplifier and a reel driver The shunt current is used because a reel motor can momentarily draw over 20 amps far exceeding the direct sourcing capabilities of a single integrated...

Page 64: ...all neither be reproduced in whole or in part without OGC s prior written approval nor be implied to grant any license to make use or sell equipment manufactured in accordance herewith SIGNAL POLARITY...

Page 65: ...ort assert and initiate forward and reverse motion at 75ips or initiate rewinding at 200ips The binary signals act through translators to apply certain voltage levels to the ramp generators The ramp g...

Page 66: ...from asserting simultaneously The illustration on this page shows the functional organization of the motion selectors and the ramp generator for 75ips movements The accompanying waveforms show the sig...

Page 67: ...binary signal REW 1 When the signal asserts a negative reference signal is applied to the ramp generator The reference voltage is removed when the control signal goes false The ramp generator changes...

Page 68: ...generator When the capstan is initially at rest the error signal that starts its motion is nearly the full output of the ramp generator As the capstan begins to accelerate the tachometer output increa...

Page 69: ...of the armature will be nearly proportional to the developed torque Since velocity is simply the integral of acceleration the capstan motor is in effect an electromechanical ntegrator its output veloc...

Page 70: ...pt at the single point at the power supply where all grounds are tied together This nearly eliminates any noise interaction that could occur between the capstan system and the write current drivers if...

Page 71: ...eries transport power supply controls and converts ac supply power to low voltage de for the transport circuits and servo motors It employs a ferro resonant transformer to provide the coarse regulatio...

Page 72: ...6 1 5 4 75 to 4 5 4 12 5 0 35 12 5 0 35 10 6 5 10 6 5 5 5 5 0 15 5 5 5 0 15 7 3 to V 24 refers to the regulation method xfmr ferroresonant transformer LS linear series pass regulator locates the sourc...

Page 73: ...uts appear at the right AC power is fused and filtered and connected to the ac relay module The module produces a low level de control voltage for the panel mounted power switch The switched control v...

Page 74: ...the following schematic diagram The control transformer is energized whenever the transport is connected to the ac power line it operates over the full range of line voltages The transformer output is...

Page 75: ...indings As the primary current rises the additional flux is short circuited through the m g etic sh t and doe not link the secondary windings This mecharusm maintains a fixed secondary flux density an...

Page 76: ...mparator stabilizes the output voltage A current sense resistor and associated transistor limit the output current to a preset maximum to protect the pass transistor from excessive power dissipation 5...

Page 77: ...age and the emitter follower acts as a current amplifier 12V OR 5 5V REGULATORS DG 04664 VI 7 OVER VOLTAGE PROTECTION Over voltage protection is applied to the 5 volt output to protect the logic circu...

Page 78: ...This page intentionally left blank Vl 8...

Page 79: ...herewith APPENDIX A TECHNICAL SPECIFICATIONS Tape Speed Data Density Start and Stop Time Speed Variation _Start Stop Distance Rewind Speed Dynamic Skew Static Skew Tape Computer Grade Reel Size Record...

Page 80: ...DGC s prior wrillen approval nor be implied to gr ant any license lo m iike use or sell equipment m iinuf iiclured in ucord iince herewith Dimensions Weight Mounting Power Cable Temperature Range Rela...

Page 81: ...This page intentionally left blank A 3...

Page 82: ...cific ations conl ained herein are the properly of DCC and shall neither be reproduced in whole or in p art without DCC s prior written approv al nor be implied lo grant any license to m alie use or s...

Page 83: ...r and switching regulators It is functionally equivalent to the current version in that it provides the same voltages and currents as well as the remote energize feature POWER SUPPLY MODULE The power...

Page 84: ...ring up the transport The large board at the front of the power supply contains the principal de regulators and the reel servo power amplifiers POWER SUPPLY MOUNTED BOARDS DC REGULATOR POWER AMPLIFIER...

Page 85: ...the servos There are 11 low voltage levels distributed throughout the transport summarized in the following table 5Vdc 15Vdc 15Vdc 12Vdc 12Vdc 6Vdc 6Vdc 10 6Vdc Vref 10 6Vdc Vref 12 20Vdc dual 12 20Vd...

Page 86: ...parallel For 220 volt ac supply nominal the split windings are connected in series The ventilation fans and the vacuum blower motor operate at 120 volts nom regardless of the supply voltage and are co...

Page 87: ...es an interrupt SCR to protect the transport servos in the event of a momentary power failure in the ac supply In such a case power to the transport restores only after the 15 volt supply bus has comp...

Page 88: ...Adc Max 0 5V P P ripple 5Vdc 25V nr 5 2 0Adc Max 0 2V P P ripple 12 20Vdc 25V nr 10 17 0Adc Max 0 75V P P ripple 15Vdc 25V nr 10 1 OAdc Max 0 5V P P ripple 12Vdc 15V reg 5 350mAdc Max 150mV P P ripple...

Page 89: ...w is stopped and the load draws power from the LC circuit until the voltage drops to a level that sets the regulator again The frequency at which the regulator toggles in this manner varies from 0 to...

Page 90: ...t voltage of a power supply it actually accomplishes this by controlling current flow The output voltage is monitored and the current flow is adjusted to maintain the desired voltage In operation a 7...

Page 91: ...SECONDARY CABLE A 008 000436 1 WL EOT BOT CABLE A 008 000437 1 WL REEL MOTORS CABLE A 008 000438 1 WL POWER SUPPLY PRIMARY CABLE A 008 000440 1 WL CAPSTAN TACH CABLE A 008 000441 1 WL TRANSDUCER CABL...

Page 92: ...This page intentionally left blank B 10...

Page 93: ...on about operating To instruct 1n a class As a student in a class As a reference manual Other procedures Did you find the material Useful YES Complete YES Accurate YES Well organized YES Well written...

Page 94: ...RY IF MAILED IN THE UNITED STATES BUSINESS REPLY MAIL Postage will be paid by DataGeneral Southboro Massachusetts 01772 ATTENTION Engineering Publications FOLD UP SECOND STAPLE FOLD DOWN FIRST CLASS P...

Reviews:

No comments

Brands by name

Popular brands

Load more brands