HP 562A User manual

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01081-1
PRELIMINARY OPERATING MANUAL
MODEL S62A
DIGITAL RECORDER
Serials Prefixed: 134-
Copy.l,h, HfWUTJ.PAClCARD CO"'PANY 1961
1501 PAGf "" L ROAD. PALO ALTO. CALIFORNIA. USA.
Printed: 9/61

Model 562A
TABLE OF CONTENTS
Section
GENERAL DESCRIPTION
I
1-1.
1-2.
1-3.
1-4.
1- 5.
1-6.
Description
Data Entry
Standard Instrument
Options Available
Power Requirements
Uses
......
Page
1-1
1-1
1-1
1-1
1-2
1-2
1-2
2-1
2-1
2 ... 1
2-1
2-1
2-1
2-1
· .
·.
. .. .
INSTALLATION.
2- • Gene ral Inforn1ation
2-2. Rack Mounting •
2-3. Connection to the ~Transistorized Counters
2-4. Connection to ~ Counters and Digital Voltmeter
2-5. Operation from Two Data Sources
2-6. Cable Fabrication
II
III
OPERATION
3 -1
3-1. Ope rating Controls
•·•3
-1
3-2. Paper Tape
3-1
3-3. Inked Ribbon
··
3-2
3-4. Taped Duplicates
••
3-3
3 -5.
Programming the Recorder
··
3-3
3 -6. Prograrnming th.e Control Board
(AI3) 3-3
3-7. Data Source Connections
3-4
3-8.
Programming the Column Boards 3-4
3-9.
Reference Voltages
3-5
3 -1 O.
Reference Voltages Adjustment
3-6
3-11. Power Supply and Internal Reference
Voltages
3-6
3-12. Printing a Minus (-)
··
3-6
3-13. Setting the Analog Controls (optional) • 3-7
3-14. Recording with Galvanometer Graphic Recorders
3-7
3-15. Using Graphic Recorders Having Different
Input Sensitivities
3-8
ii
,

Model 562A
TABLE OF CONTENTS (Cont'd)
Section
IV THEOR Y OF OPERATION •
TROUB LESHOOTING
V
4-1.
4-2.
4-3.
4-4.
5-1.
5-2.
5-3.
Introduc tion • •
Control Board Operation •
Column Board Operation.
Analog Circuitry Operation
•
Introduction
Localizing the Trouble
Semi-Conductor Replacement
Page
4-1
4-1
4 .. 1
••
4-2
• •
4-3
••••
5-1
•
5-1
•
5-2
5-2
iii

Section I Model 562A
Table 1 -1. Specifications
Accuracy:
Printing Rate:
Column Capacity:
Print Wheels:
Dri ving Source:
Print Command Signal:
Transfer Time:
Paper Required:
Power Requirements:
Dimensions:
Identical to input device used
5 lines per second, nlaximum
To 11 columns (12 available on special
order)
12 positions, numerals 0 through 9, a minus
sign, and a blank, Other symbols
available. *
Par a 11 e1 entry 4 -Ii ne BCD, 1 - 2 - 2 - 4. at her
codes available. Source reference voltage
establishes "0" state. "0" or "1" state
m'..lst not be nlore than 150 volts above or
below ground. The binary swing should be
between 4 and 75 volts.
Positive or negative pulse, 20 \J.s or greater
in width, 6 to 20 volts.
Approximately 2 rns
Standard 3 -inch roll or folded paper
115/230 volts ± 10%, 50/60 cps (4 prints per
second maximum at 50 cps)
Cabinet Mount: 20-3/4 in. wide, 12-1/2 in.
high, 18-1/2 in. deep
Rack Mount:
19 in. wide, 10-1/2 in. high,
16-7/8 in. deep behind panel
Weight:
Cabinet Mount: Net 35 lbs, shipping 70 lbs
(app roximat el y)
Rack Mount:
Net 30 Ibs, shipping 63 lbs
(app roxilna LeI y)
1-0
* See 0j) A pp Ii cat ion Not e# 32 for i nf 0r mat ion 0n s pee ia I p r i nt w h eel s .
01081-1

Model 562A
1-1. DESCRIPTION.
SECTION I
GENERAL DESCRIPTION
Section I
The Hewlett-Packard Model 562A Digital Recorder is a transistorized electro-
IT!echanical device providing a printed record of digital inforrnation. Parallel
data entry and low-inertia moving parts allow printing rates as high as 5 lines
per second, each line containing up to 11 digits; 12 digit capacity is available
on special order.
Throughout this nlanual the Model 562A will be referred to as the recorder.
1-2. DATA ENTRY.
Standard input for the recorder is parallel-entry 4-line BCD code, either 1224
or 1248. Input to the recorder is through rear-l1'.lounted connectors. Internal
connectors route the inforn1ation to any desired sequence of columns. Each
column has binary storage for one decimal nunlber.
When a print COITlmand is supplied, each storage unit assumes the condition of
the decade counting unit (or other driving source) connected to it. The data
transfer takes place in approximately 2 milliseconds, after which tinle the
d riving source is free to gather more infornlation.
1-3 . STANDARD INSTRUMENT.
Each storage unit is mounted on a plug-in board (column board) with a de-coding
matrix. The nlatrix converts the stored data into positioning inforIT!ation for
the print wheels. The recorder is supplied to translate 1224 BCD codes, but
other 4-line codes are accoIYlmodated by substituting plug-in boards. Unless
otherwise specified, the recorder is supplied from the factory with the following:
a. Six +1224 coluIYln boards.
b. Printer nlechanism, 11 print wheels and associated components, five
prints/second with 60 cps power line frequency.
c. One input connector at rear of recorder JI01.
d. One input cable.
e. One control board.
f. One power supply board.
01081-1
1-1

Section I
1-4. OPTIONS AVAILABLE.
The following options are available:
a. + or -1224 column boards.
b. + or -1248 column boards.
c. Analog circuitry.
d. Pinion gear, allows 5 prints per second with 50 cps power.
Model 562A
e. Input connector (J201) and associated connectors (for dual input operation
or over 9 -column capacity).
f. Data input cable.
1-5. POWER REQUIREMENTS.
The recorder has been designed to operate frorr! 115/230 volt, 50/60 cps power.
A switch, located at the rear of the recorder selects operation for either 115 or
230 volts.
The three-conductor power cable supplied with the instrument is terminated in
a three-prong polarized male connector recommended by the Electrical Manu-
facturers' Association (NEMA). The third contact is an offset round pin, added
to a standard two-blade ac plug which grounds the recorder chassis when used
with the proper receptacle. An adapter should be used to connect the NEMA
plug to a standard two-contact receptacle. When the adapter is used, the ground
connector becomes a short green lead. The green lead should be connected to
a suitable ground for protection of the operating personnel.
1-6. USES.
Because of the extreme flexibility of the recorder, it can be used with electronic
counters, digital voltmeters etc. or a wide variety of individual and system
applications. The recorder will operate with + or -1224, + or -1228 BCD, and
10 -line code information depending on column boa rd s installed. Two separate
sources, unsynchronized, can be used to provide data if option e is installed.
The recorder supplies the synchronization. When the analog circuitry, option c,
is installed, the operator may select analog voltage of columns 1 through 9 in
3 -column groups.
1 -2
01081-1

Model 562A
SECTION II
INSTALLATION
2-1. GENERAL INFORMATION.
Section II
Section II contains information relating to installation and input connections.
2-2. RACK MOUNTING.
If the recorder is to be rack mounted, be certain to allow sufficient open space
for cooling air to enter and exhaust. Do not rnount the recorder next to equip-
ment which will discharge hot air into the recorder air intake.
2-3. CONNECTION TO THE $p TRANSISTORIZED COUNTERS.
The recorder may be directly connected to the ~ transistorized counters by
means of the input cable supplied with the recorder. The transistorized
counters have the correct connector installed. Recorder connector J101 is
connected to the counter recorder connector. If a second transistorized
counter is to be connected to the recorder, connection is made froIn the second
counter to recorder connector, J201. The transistorized counter output is
+1224 BCD.
2-4. CONNECTION TO rfiJ COUNTERS AND DIGITAL VOLTMETER.
If the recorder is to be connected to the above tube type instruments a modifi-
cation kit can be installed. The kit provides a +1224 BCD output.
2-5. OPERATION FROM TWO DATA SOURCES.
The recorder can be operated fronl two data sources, synchronized or unsyn-
chronized, by connecting the data inputs to connectors J101 and J201. The two
data inputs can be ±1224 or ±1248 code. The appropriate coluInn boards Inust
be installed in the proper connectors in the recorder.
2-6. CABLE FABRICATION.
Connection of the recorder to data sources other than the above Inay require
construction of a cable terminated with a connector that will mate with the
recorder connectors. Use small gage telephone-type wire. Number 26 gage
wire meeting MIL-B -76A, with 7 strands #34 gage wire, tinned after stranding,
with 10 SoC plastic insulation has been found satisfactory. Select a sy stematic
color code for wires to avoid errors. Use care in soldering. Repairing faulty
connections after all wires are soldered is very difficult. A length of # 14 gage
wire makes an excellent soldering tip for use on closely-spaced connector terrninals.
01081-1
2 -1/2-2

Model 562A
SECTION III
OPERATION
3-1. OPERATING CONTROLS.
The operating controls consist of the following:
POWER ON,
supplies power to the recorder when in the ON position.
Section III
RECORD ON,
allows the printer mechanism to operate when in the ON position. When the
switch is in the spring-loaded position(down), the recorder prints at maximum
rate. The middle p osition is a standby position(allows analog to be taken).
SPACE SELECTOR,
selects the number of spaces between readout prints.
PAPER ADVANCE,
manually advances paper.
ANALOG CONTROLS,
(optional) refer to text.
3-2. PAPER TAPE.
Special ~folded tape is recommended for use with the recorder. High-quality
standard 3 -inch rolled adding machine type may also be used.
Folded tape permits convenient take -up in the paper drawer and allows easy
inspection of any portion of the type. It is perforated at each fold to allow neat
separation of portions of recorded data. Folded tape may be reversed and re-
run to use both sides. With single spacing, about 15, 000 prints can be made
on one side of a folded pad. One pad will last about 40 minutes at maximum
print rate.
To install the paper tape proceed as follows:
a. Open front panel.
b. Load paper in compartment.
c. Fold paper back one inch and crease. Insert paper between roller and
guide plate.
01081-1 3-1

Section III
Model 562A
d. Manually advance paper. Paper will feed easier and can be reversed with
SPACE SELECTOR set to "0".
e. Feed paper under inked ribbon.
f. Feed paper through slot. Close front panel.
g. Collect printed paper in drawer.
Follow these additional instructions if roll tape is used:
a. Insert spindle through roll. Spindle is taped to bottom of paper compart-
ment when instrument is shipped from the factory.
b. Hang roll by ends of spindle from ledges on both sides of paper compartment.
c. Paper must feed out from the bottom of the roll.
d. Continue with loading.
To feed paper rapidly use the PAPER ADVANCE thumb wheel. To manually feed
paper backward, set the SPACE SELECTOR to "0" and roll the PAPER ADVANCE
wheel in the reverse (up) direction. Paper feed may be reversed on!l. with the
SPACE SELECTOR set to "0".
Be sure paper is inserted squarely in the paper feed mechanism to prevent
jamming. If paper doe s not feed smoothly, place the RE CORD switch in the
cente r position, and re move all paper from the feed mechanism. Use tweezers
to pick out torn bits of paper.
3-3. INKED RIBBON.
The printer mechanism uses a special heavily-inked silk ribbon available from
the Hewlett-Packard Company. Standard typewriter ribbon on an Underwood
spool, with reversing rivets near the ribbon ends, may also be used; however,
impressions will be lighter than with the Hewlett-Packard ribbon.
To install new ribbon, proceed as follows:
a. Open the hinged front panel to gain access to the printer mechanism.
b. Loosen the two printer mechanism retaining screws located on the lower
front corners of the mechanism by turning 1/4 turn counterclockwise.
c .. Slide mechanism out of cabinet until ribbon spools are readily accessible.
d. Wind all the ribbon onto one spool.
3-2
01081-1

Model 562A
Section III
01081-1
e. Shift the two ribbon spool retaining springs away from the spools, and
remove spools.
f. Take the ribbon out of the mechanism. Save the empty spool.
g. Hook end of new ribbon on empty spool. Wind about 10 inches of
ribbon on the spool so that the rever sing rivet is on the spool.
h. Install new ribbon by feeding it over the ribbon rollers and between the
print wheels and paper tape.
i. Feed ribbon through the slots in the reversing arms and around the
lower guides. Ribbon must be twisted 90
0
between the ribbon roller and the
slot in the rever sing arm.
j. Place ribbon spools on their shafts. Fasten spools in place with the
spool retaining springs. Ribbon must feed out from the bottom of each spool.
k. Replace printer mechanism in cabinet and tighten retaining screws.
3-4. TAPE DUPLICATES.
Transparent paper, ~stock no. 9251-0052 is recommended for use in the
recorder. This paper produces much less paper dust and copies can be
easily made with duplication machines. If duplicate tape records are
required from standard paper, contact print duplicating methods, such
as the ozalid process, can be used by printing directly from the original
tape records.
3-5. PROGRAMMING THE RECORDER.
The recorder can be programmed to accept different codes if the proper
column boards are installed. The column boards may be inter-mixed if desired.
The standard recorder is supplied with six +1224 BCD column boards, with
connectors installed to accept a total of nine column boards. If more than
nine column operation is desired, J201 must be installed with the connectors
that attach to the rear of the column boards (PIIO-PIl5).
Normally JIOl supplies data to column boards Al-A9, but connectors PIOl-
PI09 can be connected to supply data to any of the column boards the operator
desires. J201 can supply data to any of the remaining column boards. Con-
nectors PIIO-Pll5 can be connected to supply data to six column boards.
3-6. PROGRAMMING THE CONTROL BOARD (AI3).
Connectors P20l and P202 supply control signals to the data sources, and
return data source signals to the control board. Connector P20l is con-
3-3

Section III
Model 562A
nected to one data source through JI01. and P202 to a second data source
through J201. The control board senses when commands from both sources
have been received, then starts the printing cycle. If only 'one data source is
used, the control board connector that is not being used must be disconnected,
otherwise the recorder will not operate but will wait until the control boarq
receives a second print command signal. When the control board connector
that is not being used is disconnected, the associated print command binary
remains in the proper state of unbalance. Thus a print command is required
from only one data source to start the printing cycle.
3-7. DATA SOURCE CONNECTIONS.
Data can be supplied continuously from two data sources. If six column read-
out is desired for one data source and five column readout is desired for the
second data source, then one data source is connected to JI01 and the other
data source to J201. The column board connectors can be connected as the
operator desires. Other combinations the operator may want can be had by
changing the connectors at the rear of the column boards.
3-8. PROGRAMMING THE COLUMN BOARDS.
The following tables are for 1224 and 1248 BCD code.
Table 3 -1. 1224 Column Board
Character
Binary Input
to be
D C BA
Printed
Weight
4 2 21
0 0 0 00
10001
20010
30011
40110
501 1 1
61 1 0 0
7110 1
81 1 1 0
91111
-10 0 1
blank
10 0 0
3-4
Table 3 -2. 1248 Column Board
Character Binary Input
to be DC B A
Printed
Weight
8421
00 0 00
10 0 01
20010
30011
4010 0
50101
60110
70111
8 1 0 0 0
91001
-1011
blank 1010
01081-1

Model 562A
The following notes refer to tables 3 -1 and 3 -2:
1 and 0 definitions
1) 1 indicates "1" level binary input.
2) 0 indicates "0" level binary input.
Section III
"1" and "0" levels (BCD input)
1) In a +1224 code, the" 1" level is positive with respect to the "0" level.
2) In a -1224 code, the" 1" level is negative with respect to the "0" level.
The + or - prefix is deterrnined by the polarity of the" 1" level with respect
to the "0" level.
3-9. REFERENCE VOLTAGES.
Input to the binaries is through gates which are controlled by two dc -biasing
signals which control the passage of transfer pulses. One of the biasing signals
is the BCD data input and the other is a reference voltage. The transfer pulses
are internally-generated within the recorder. The inputs to the binaries are
capacitively-coupled and may be floating with respect to chassis ground. The
reference voltage is thus required to establish a point to which the BCD sig'nal
is referred. Two reference voltages are required in the data storage system
and should generally be the steady dc values of the 0 and 1 states of the BCD
input signal. This relationship of reference to BCD signal is shown in figure
3-1 for a negative-going signal equal to the 1 level.
"0"
"1"
SIGNAL TO BE WITHIN
± 150V TO GND.
POS. OR "0" REFERENCE
NEG. OR" 1" REFERENCE
It I" EQUALS
NEGATIVE-GOING
RO
Figure 3 -1. Reference Levels.
01081-1 3-5

Section III
3-10. REFERENCE VOLTAGE ADJUSTMENT.
Model 562A
The input voltage applied for any column board must not exceed 150 volts. That
is the refe renee voltage plus the B CD It 1 It level should not be greater than 150 volts.
For instance, if the BCD swing is from 100 volts (tiD" level) to 160 volts (til" level)
then attenuation must be introduced to reduce the "0" level to 94 volts and the
"1" level to 150 volts. The minus reference voltage can then be adjusted for
94 volts. The plus reference level must then be adjusted to 150 volts.
Before a reference voltage can be chosen, the "0" and" I" levels of the equip-
ment supplying the BCD signals must be known. For instance if the recorder
is connected to a binary counter with a -1248 code, each column board will be
driven by a decade in the counter. Sometimes binaries in the decades have
different" 1" and" 0" levels, thus a proper reference voltage must be chosen.
If the column board is a -1248 code, then the -reference voltage must be chosen
that includes the "1" levels applied to the A, B, C, and D binaries. A +reference
voltage must be chosen that will include the "0" levels for the A, B, C, and
D binaries.
If high impedance reference levels are used (above 5000 ohms), suitable by-
passing, providing a time constant of 150 ~s, should be used. If the BCD drive
is derived from an unregulated supply, then it is desirable to obtain the reference
voltage from the same unregulated supply.
3-11. POWER SUPPLY AND INTERNAL REFERENCE VOLTAGES.
The power supply board, A16, supplies the de voltages required by the recorder.
The power supply also has provisions for providing reference voltages of -9 to
+17 volts. The operator can select a value of resistors or breakdown diodes
needed to provide the proper reference voltages. Connectors P301 and P302
(optional) supply the reference voltages to the column boards. When using an
external reference voltage, connectors P30l and P302 must be disconnected from
the power supply board if resistors are installed. Unless specified by the
customer, resistors are not installed. The proper mounting holes are in the
power supply board and the operator can install the resistors or break-
down diodes required to give the desired voltage.
3 -12. PRINTING A MINUS (- ).
The recorder will normally print a blank with no BCD input. If the operator
wishes to print a -(minus) for a 1224 code, in place of a blank, proceed as follows:
In table 3-1 under the column headed "character to be printed", find -(minus).
Under the "Binary Input" column, the - charac ter must have a "l" input for
the A and D binaries. If the column board is a +1224 code, then the external
voltage applied to the A binary input must be at least 4 volts more positive
than the negative reference voltage. Since the D binary has a 11 I" supplied
3-6
01081-1

Model 562A
Section III
01081-1
by the transfer pulse when the nOll level is not present, no external voltage is
required for the D binary. A -1224 code req uire s the same voltage s but of
diffe re nt polarity.
If the column board is a +1248 code, in table 3-2 find -(minus). Under the
"Binary Input" column, the - character must have a "l" input for the A, B,
and D binaries. An external voltage applied to the A binary must be at least
4 volts more positive than the negative reference voltage. The Band D binaries
do not require an external voltage as the transfer pulse supplies the" 1" level
when "0" level is not present. A -1248 code requires the same external
voltages, but of different polarity.
3-13. SETTING THE ANALOG CONTROLS (ortional).
The POTENTIOMETER RECORDER binding posts on the 562A are designed
to operate potentiometer type (voltage operated) recorders having lOO-millivolt-
full-scale sensitivity, and greater than 50K ohm input resistance. The 562A
can also drive recorders having other values of input sensitivity and resistance
by making minor addiqons or modification to the POTENTIOMETER RE-
CORDER ANALOG OUTPUT.
To use the 562A on a potentiometer recorder, proceed as follows:
a. Set the COLUMN SELECTOR to include the three number columns to
be recorded gr aphically.
b. Connect the potentiometer recorder to the POTENTIOMETER RECORDER
binding pos ts on the 56 2A.
c. Set the OPERATE lever switch to the G8.LV. ZERO position (the GALV.
ZERO control has no effect on the POTENTIOMETER RECORDER output) but
does supply zero output at potentiometer jack.
d. Zero set the potentiometer recorder with its own controls.
e. Set the OPERATE lever switch to the CALIBRATE position.
f. Adjust the CALIBRATE control to obtain full-scale deflection of the
recorder pen.
g. Repeat steps c, d, e, and f.
h. Set the OPERATE lever switch to OPERATE. The graphic recorder
will now plot the number columns indicated by the COLUMN SELECTOR.
3-14. RECORDING WITH GALVANOMETER GRAPHIC RECORDERS.
The GALVANOMETER RECORDER output jack on the 562A is designed to
operate galvanometer type (current operated) recorders having I-milliampere-
3-7

Section III
Model 562A
3-8
full-scale se nsitivity and Ie s s than 5000 ohnlS input re sis tance. The 562A can
also drive recorders having other values of input sensitivity and resistance by
making minor additions or modifications to the GALVANOMETER RECORDER
ANALOG OUTPUT.
To use the 562A with a galvanometer recorder, proceed as follows:
a. Before connecting the recorder to the 562A, deternline which three of the
number columns are to be plotted. Then set the COLUMN SELECTOR to in-
clude these three number columns.
b. Zero set the galvanometer recorder with its own controls.
c. Connect the recorder to the GALVANOMETER RECORDER jack using
a standard, 1/4-inch diameter three-circuit phone plug. The positive recorder
terminal is connected to the ring contact on the plug, and the negative terminal
to the tip on the plug.
d. Set the OPERATE lever switch to the GALV. ZERO position.
e. If necessary, zero set the recorder with the GALV. ZERO set control
on the 562A.
f. Set the OPERATE lever switch to the CALIBRATE position.
g. Adjust the CALIBRA TE control to obtain full-scale deflection of the
recorder pen.
h. Set the OPERATE lever switch to the OPERATE position. The recorder
will now plot the number columns indicated by the COLUMN SELECTOR.
3-15. USING GRAPHIC RECORDERS HAVING DIFFERENT
INPUT SENSITIVITIES.
To use a potentiometer recorder having greater than specified voltage sensi-
tivity, shunt the recorder with a value of resistance which results in full-scale
deflection of the recorder pen while the 562A is set to CALIBRATE and the
CALIBRATE control is cente red.
Potentiometer recorders having less than 50K ohm input resistance may be
used, but the POTENTIOMETER RECORDER output will than provide less
than 100 millivolts for full-scale deflection. The internal resistance at the
POTENTIOMETER RECORDER output is approximately 2500 ohms and when
loaded with this value, provides only 50 millivolts for full scale deflection.
If the potentiometer recorder has sufficient sensitivity to operate with the
lower input level, no modification is required to use the recorder. However,
as the external resistance on the POTENTIOMETER RECORDER binding posts
is decreased, so is the range of the CALIBRATE control, until at sonle low
resistance it may be necessary to provide an external calibrating control
01081-1

Model 562A
Section III
01081-1
consisting of a potentiometer connected as a variable shunt for the signal
which is fed to the graphic recorder.
If a potentiometer or galvanometer recorder is to be used which requires
slightly greater output voltage or current, it is possible to increase the
562A ANALOG OUTPUT by changing the values of certain resistors in
the analog circ ufts.
3-9/3-10

Model 562A
SECTION IV
THEOR Y OF OPERATION
4-1. INTRODUCTION.
Section IV
Operation of the 562A is dependent upon a series of timing and reference volt-
ages. The timing voltages are supplied by the control board (Al3). Reference
voltages can be supplied by the power supply (A14) or by an external source.
The following paragraphs will describe the functions of various circuits in the
recorder.
4-2. CONTROL BOARD OPERATION.
Operation of the recorder is dependent upon a series of timing voltages
developed by the control board. Refer to the functional diagram, figure 5-2.
Assume the data source initiates a print command. Print Command Binary
Number 1 changes state and immediately supplies the data source with a disable
voltage. Assume Print Command Binary Number 2 has its input connector
arranged so only one print is required. The Print Scan Schmitt is in the
proper state because the shutter is open. The Print Scan Schmitt applies the
proper signal to the "And" Gate. The "And" Gate conducts and causes the
Clutch Binary to change state. The clutch solenoid starts to energize. When
the Clutch Binary changes state, a signal is applied to the Delay Multivi-
brator (2MS). The output of the 2 ms delay multivibrator produces a reset pulse
which is applied to the storage binaries. This removes stored information and
sets the storage binaries in the proper state to receive new information. The
output of the 2 ms delay multivibrator is also applied to a 60 J-Ls delay multi-
vibrator. The output of the 60 J-LS multivibrator is applied to the storage binary
gate diodes by way of the + and - Transfer Amplifiers, then data transfer takes
place. The output of the 60 f.LS multivibrator is also applied to the
Print Command Binaries and resets them. While this action is occurring, the
clutch solenoid is completing its pull-in cycle. When the clutch solenoid has
engaged the clutch, the clutch will remain engaged for one complete revolution
of the clutch assembly because of mechanical action. As the clutch assembly
rotates, the shutter closes, de-energizing the photo conductor. This causes
the schmitt to change state, initiating the scan signal. The scan signal then
resets the clutch binary and opens the Inhibit Gate circuits which can allow the
pawl magnets to energize. When the brush senses the correct voltage, the pawl
magnets de -energize and lock the print wheels at the proper position. Then the
character is printed as the clutch assembly finishes its one revolution, disengages,
and opens the shutter. The photo conductor is energized and the system is ready
for the next print command.
01081-1 4-1

Section IV
4-3. GOLUMN BOARD OPERATION.
Model S62A
4-2
The following theory is for operation of a -1248 code column board. Assume
a data source has initiated a print command, the AND GATE in the control
board conducts, and the clutch solenoid starts to energize. A signal is then
applied to the 2 MS DELA Y lY1ULTIVIBRA TOR by the clutch binary. After
2 ms, the nlultivibrator applies a positive reset pulse to the column boards.
The binaries reset as follows:
A
BINARY:
Q 101, on; 0102, off
B
BINARY: a 1 03, off; 0104,
on
G
BINAR Y: a 105,
on; a 106, off
D
BINARY:
Q 107,
off;
a 108, on
The data source is supplying bcd information to the four binarie s. Suppose
the bcd information supplied is for the decimal number 8. According to
table 3-1, "0" level information will be supplied to the G, B, and A binaries.
The D binary will have "l" level information supplied. The "0" or "l'" do not
change the state of the binaries. The - and + transfer pulses cause the binaries
to change state if the 1t0" or II lit levels needed are present. At the D binary,
if the "1" level is pre sent GR 1 04 is forward biased and - transfer pulse will go
through diode gate GR 1 04. Since a 107 is off, the D binary will change state,
a107 on and a108 off.
The G binary has "0" level information applied to diode gate GRI03. A+ trans-
fer pulse is applied to GRI03. Since the "a" level information applied to GRI03
is equal to the + reference voltage, the diode will pass the + transfer pulse.
Thus QIOS is off and al06 is on.
The B binary has" 0" level information applied to diode gate GR 1 02. Since the
"Olt level information is (at least 4 volts) more positive than the -reference
voltage, diode GRl02 is reverse biased and will not pass the - transfer pulse. The
binary will not change state. Transis tor a 103 re mains off and a 104 re nlains on.
The A binary has "a" level information applied to diode gate GRIOI. The "0"
level mllst be equal to the positive reference voltage. This causes GRlOI to
be forward biased and pass the + transfp.r pulse. The A binary changes state,
QIOI off and QI02 on.
Three of the halves of the binaries that are "on" will return, through matrix
resistors, to pin 11 of connectors XAl-l to XA12 -1. This is the line which
corresponds to the decimal number 8. In this case, R161, R175, and Rl99
return to the line for the decimal number 8. These resistors make the line
for the number 8 go to app roximatel y+ 15 volts. Diode gate G Rl a5 and G Rl Oh
sense when the line gets to approximately +15 volts and cause amplifiers al09»
a 110, and Q III to de -energize the pawl magnet. The pawl then locks the
01081-1

Model S62A
Section IV
print wheel at that position. The number is then printed. When the data source
initiates another print command, the scan signal occurs a short time later and
causes amplifiers 0109,0110, and 0111 to energize the pawl magnet if the
data input has changed. The print wheel rotates. The magnet remains energized
until diode CRI0S has +lS volts applied from the matrix.
4-4. ANALOG CIRCUITRY OPERATION.
Sinc e the column board s contain stored binary information, an analog function
can be derived to drive a strip chart recorder. The analog circuitry provides
the following:
a. A graphic presentation whereby the trend of recorded data can be seen at
a glance.
b. Three digits of analog information where full scale on the recorder may
be a few parts per million of the original printed reading.
c. A recording where an increasing numerical count is always an upward
direction on the strip chart recording.
d. An analog recording which is always on scale.
To derive the analog voltage a switching arrrangement is used which utilIzes
the stored binary data from three consecutive columns of the printed data.
Any three of the first nine columns may be used as well as the first two right
hand digits.
The binary output data is weighted according to the code required by the
storage units. Four resistors are used to develop a staircase function from
the four storage binaries. The four weighting resistors are in the ratio 4221.
Refer to the analog circuitry schematic. Each of the three storage decades
then produces a staircase function with a level proportional to the numerical
value of its stored binary data.
The three staircase voltages are then mixed in proportion to their decade
value or in the ratio of 1, 10, 100, to produce a single staircase function
1000 part in amplitude. Each discrete step then represents. 10/0 of full scale
and for practical purposes is an analog function. This output voltage is then
attenuated and applied directly to a potentiometer type strip chart recorder.
The analog signal is also applied to an amplifier whose output can be used to
drive a1 rna type galvanometer recorder.
Diode clamps insure accurate voltage levels before mIXIng. Compensation
elements maintain constant output over wide temperature extremes.
01081 -1
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