Centronics 306 User manual

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MODEL
MARCH 1976
Centronics No . 37400040 -Rev F
306 · PRINTER
l:EnTRDnll:S
data computer corp.
HUDSON, NEW HAMPSHIRE , 03051
TELEPHONE (603) 883 - 0·111

MODEL
306
PRINTER
REVISION F
MARCH 1976
THE INFORMATION CONTAINED HEREIN IS
PROPRIETARY AND IS NOT TO BE RELEASED
OR REPRODUCED WITHOUT WRITTEN PER-
MISSION OF CENTRONICS data computer corp.
I:EnTROnll:S
data computer corp.
HUDSON, NEW HAMPSHIRE 03051
TELEPHONE [phone]

TABLE OF CONTENTS
SECTION 1
INTRODUCTION
Section
1.1
1.2
1.3
GENERAL DESCRIPTION. .
LOGIC FLOW DIAGRAM .
PRINTER OPERATION . .
1. 3.1
1.3. 2
1.3.3
Character Printing .
Paper Movement. .
Special Functions.
1.4 SYSTEM FEATURES
1.4.1 Specifications Summary. . .
1.4.2 Standard and Optional Features
1.5 PHYSICAL DESCRIPTION . . . . . . .
2.1 SITE PREPARATION
2.2 SHIPPING CRATE
4.1 INTRODUCTION
4.2 BASIC TIMING
SECTION 2 AND 3
INSTALLATION AND OPERATION
SECTION 4
THEORY OF OPERATION
-1-
1-2
1-2
1-3
1-3
1-4
1-5
1-6
1-6
1-7
1-7
2-1
2-2
4-1
4-1

TABLE OF CONTENTS (cont'd)
Section
4.3
INITIALIZING THE PRINTER. . . . . .
4.3.1
Prime. . . . . .• . •••
4.3.2 Select • . . . . . . . . .
Page
4-3
4-3
4-5
4.4 DATA INPUT .•......•.. 4-6
4.4.1 Data Input Timing. . .. ...•.. 4-6
4.4.2 Busy .... ......•.. 4-9
4.4.3 Function Decoder. . . . . . . . . . .. 4-10
4.5
4.6
4.7
SHIFT REGISTER (BUFFER) .
CHARACTER PRINTING. . .
4.6.1
. 4.6.2
4.6.3
4.6.4
4.6.5
Initiating the Printer Operation. ....
Character Registration and Timing . .•.
Character Generator (ROM) ...... .
Print
Head Operation. . . . . . . . . . .
Power Driver Circuits . .. ...
PAPER MOVEMENT . • .
4.7.1
4.7.2
4.7.3
4.7.4
4.7.5
Line Feed . . . .
Form Feed • . . . • . . •• ...
Vertical Tab . . . . . . . . . . . . .
Vertical
Format Unit (Optional) .....
Line Feed Solenoid Driver. . . . .
4.8
SPECIAL FUNCTIONS • . .
4.8.1
4.8.2
4.8.3
4.8.4
Bell (Optional) . . . . .
Delete . . . . . . . . . . • .
+35V Power Supply (Unregulated) .
Motor Control (Optional) . . . . . . . . .
4.9
POWER SUPPLIES
4.9.1
4.9.2
4.9.3
+5V Regulator. . . .
+12V and -12V Regulators . .
+35V Power Supply (Unregulated) .
4.10
OUTPUTS FROM LSI CHIPS (ME25 AND ME16) . .
4.10.1
LSI Chip ME25
4.10.2 LSI Chip ME16
-ii-
4-12
4-14
4-14
4-17
4-18
4-21
4-22
4-23
4-25
4-26
4-28
4-28
4-29
4-30
4-30
4-30
4-31
4-31
4-33
4-34
4-34
4-34
4-38
4-38
4-41

TABLE OF CONTENTS (cont'd)
SECTION 5
REMOVAL REPLACEMENT AND ADJUSTMENT PROCEDURES
Section
5.1
5.2
6.1
6.2
6.3
INTRODUCTION.
· · ·
MECHANICAL ASSEMBLIES.
5.2.1 Carriage Mechanism
5.2.2 Platen (Figure AB)
· · ·
5.2.3
Paper Pan (Fi gure AC). . . · ·
5.2.4
Driving Mechanism (Figure AD, Part 1).
5.2.5 Driving
Mechanism (Figure AE, Part 2).
5.2.6 Idler Pulley Assembly (Figure AF) .
5.2.7 Reed Switch (AG)
· ·
5.2.8 Printer Base (Figure AH) . .
..
5.2.9 Frame (Figure AI)
· ·
5.2.10 Paper Feed (Figure AJ). .
5.2.11
Pin Feed Unit (Figure AK).
5.2.12 Ribbon Feed (Figure AL)
·
5.2.13 Cover (Figure AM)
· · · ·
5.2.14 Operator Panel (Figure AN)
· · ·
5.2.15 Electrical Components (Figure AO)
5.2.16 Electrical Components (Figure AP)
·
5.2.17 Electrical Components (Figure AQ) . · . . .
5.2.18 Print
Head and Associated Assemblies
(Fig. 8-19)
5.2.19
5.2.20
5.2.21
Motor Control Assembly Option . .
Vertical
Format Unit (VFU) - Option
Printer Drive Mechanism, Model 306.
SECTION 6
MAINTENANCE
ADJUSTMENTS. •. ...
PREVENTIVE MAINTENANCE . . . .
TROUBLESHOOTING GUIDE.
SECTION 7
· . .
DRAWINGS AND LISTS OF MATERIALS, ELECTRICAL
-iii-
.
.
Page
5-1
5-1
5-2
5-6
5-9
5-11
5-14
5-21
5-24
5-27
5-27
5-29
5-32
5-34
5-45
5-45
5-46
5-46
5-46
5-46
5-51
5-52
5-54
6-1
6-2
6-8
7-1
Rev. E

Section
A
B
TABLE OF CONTENTS (cont'd)
SECTION 8
MECHANICAL DRAWINGS AND PARTS LISTS
APPENDICES
SIGNAL GLOSSARY. . . . . . .
PARALLEL INTERFACE SPECIFICATIONS. .
-iv-
8-1
A-I
B-1

Figure
1-1
1-2
1-3
1-4
1-5
1-6
1-7
1-8
1-9
2-1
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
4-12
4-13
4-14
4-15
5-1
5-2
5-3
5-4
LIST OF ILLUSTRATIONS
Model 306 Printer (Top and VFU Covers Removed).
Basic Block Diagram.
Printing the Letter (H) .
Print Head Components .
Paper Movement Mechanism .
Left Front
View of 306
Right Front View of 306 .
Rear View of 306
Rear View (306 Logic/P.S. Board Removed).
Printer Dimensions .
Model 306 - Block Diagram.
Prime Timing
Input Data Timing - No Busy Condition
Input
Data Timing - Causing Busy Condition .
Forward Clutch Interconnection Diagram .
Character
Timing
Normal and Elongated Characters.
Print Head Timing .
Line Feed Timing
Form Feed and Vertical Tab Timing .
VFU Tape Reader Amplifier (Located in VFU) •
Motor Control Timing .
+5 Volt Regulator Interconnection Diagram .
~12V Regulators Interconnection Diagram .
+35V Unregulated Supply Interconnection Diagram .
Carriage
Movement Adjustments .
Timi ng Fence Mounting, Model 306 .
Adjustment of
Timing Belt (AD-15) (View from back of
printer, forward) .
Adjustment of Timing Belt (AD-41) (View from back of
printer, forward) . . . . .
-v-
Page
1-2
1-3
1-4
1-4
1-4
1-8
1-8
1-9
1-9
2-1
4-2
4-4
4-7
4-8
4-15
4-16
4-20
4-22
4-25
4-27
4-29
4-32
4-35
4-36
4-37
5-5
5-8
5-13
5-14
Rev. E

LIST OF ILLUSTRATIONS (cont'd)
Figure
5-5 Main Motor Belt Adjustment (AE-9). 5-18
5-6 Forward Clutch Adjustment (Air-Gap) . 5-19
5-7 Bushing End-Play Adjustment for (Forward Clutch Shaft
Air-Gap and Preload Clutch) 5-19
5-7A Location of Drive Pulley Bracket (AE-21) . 5-20
5-8 Torque Limiting Device (Brake) 5-24
5-9 Reed Switch Assembly, Left (AG) . 5-25
5-10 Left Reed Switch (AG-1) Static-Adjustment . 5-26
5-11 Two Adjustments, Paper Feed Mechanism (AJ). 5-31
5-12 Locating Idler Pulley Assembly 5-37
5-13
Locating Dimension for Ribbon Feed Rack. 5-38
5-14 Rack and Pinion Adjustment, Ribbon Mechanism . 5-39
5-15 Locating Dimension for Left Ribbon Holder Plate with
Respect to Rear Guide Bar 5-40
5-16 Locating Dimension for Right Ribbon Holder Plate with
Respect to Rear Guide Bar 5-40
5-17 Left Operator and Stopper Adjustment. 5-41
5-18 Ribbon Feed Plate and Guide Bar (Left Side) . 5-42
5-19
Adjusting Nuts for Right Pawl Operator Movement . 5-42
5-20 Right Pawl Operator Starting Position . 5-43
5-21 Pawl, Ratchet and Cam Movement. 5-44
5-22 Spur on Left Releaser.(AL-174) and Roller (AL-46). 5-44
5-23 Fibre Optics Head, Adjustment from Optic Fence . 5-50
5-24 Fibre Optics Head Alinement and Flexible Timing Fence. 5-50
5-25 Motor Control Location and Installation. 5-51
5-26 Removal/Replacement of Drive Shaft 63060142-5001 and
Couplings 63060144-2002 for VFU Assembly . 5-53
5-27 Paper Tape Reader Adjustment . 5-54
5-28 Printer Drive Mechanism, Model 306 . 5-55
7-1 Schematic Diagram, Logic/P.S. Board (+5V) (Sheet 1 of 4) 7-3
7-2 Schematic Diagram, Logic/P.S. Board (+5V) (Sheet 2 of 4) 7-4
7-3 Schematic Diagram, Logic/P.S. Board (+5V) (Sheet 3 of 4) 7-5
7-4
Schematic Diagram, Logic/P.S. Board (+5V) (Sheet 4 of 4) 7-6
7-5 Schematic Diagram, Power Driver Board (Sheet 1 of 2) . 7-7
7-6 Schematic Diagram, Power Driver Board (Sheet 2 of 2) . 7-8
Rev. E
-vi-

Figure
7-7
7-8
7-9
7-10
7-1.1
7-12
7-13
7-14
7-15
7-16
7-17
7-18
7-19
7-20
8-i
8-1
8-2
8-3
8-4
8-5
8-5A
8-6
8-7
8-8
8-9
8-10
8-11
8-12
8-13
8-14
8-15
LIST OF ILLUSTRATIONS (cont'd)
Page
Schematic Diagram, Video Amplifier. · 7-9
Interconnection Diagram, Connector Card . . 7-10
Wiring Diagram, Printer Mechanism. . 7-11
Schematic Diagram, Elapsed Time Indicator (Option) . . 7-12
Logic/Power Supply Board Connections . . 7-13
PC Board Ass'y, Logic/Power Supply Board (Sheet 1 of 2). 7-15
PC Board Ass'y, Logic/Power Supply Board (Sheet 2 of 2). 7-16
PC Board Ass'y, Power Driver Board (Sheet 1 of 2). . 7-20
PC Board Ass'y, Power Driver Board (Sheet 2 of 2).
PC Board Ass'y, Video Amplifier and Cable Ass'y .
PC Board Ass'y, Connector Card
PC Board Ass'y, Elapsed Time Indicator (Option) .
Cable Ass'y, Data Input .
Cable Ass'y, Computer Input.
Model 306 Subassemblies •
Carriage - AA
Platen - AB
Paper Pan - AC .
Driving
Mechanism (Part 1 of 2) - AD .
Driving
Mechanism (AE, Part 2) (This Drawing Applies
to
Air-Gap Clutch Only)
Driving Mechanism (AE, Part 2) (This Drawing Applies
to Preload Clutch
Only)
Idler Pulley - AF
Reed Switch - AG
Base - AH
Frame - AI
Paper Feed - AJ .
Pi n Feed - AK.
Ribbon Feed - AL (Part 1 of 2) .
Ribbon Feed - AL (Part 2 of 2) •
Cover - AM
Operator Panel - AN.
-vii-
· 7-21
· 7-23
· 7-25
· 7-27
· 7-29
· 7-31
· 8-3
· 8-5
· 8-7
· 8-9
• 8-11
· 8-13
· 8-15
· 8-17
8-19
· 8-21
· 8-23
8-25
· 8-29
· 8-31
· 8-32
· 8-35
· 8-37
Rev. E

Figure
8-16
8-17
8-18
8-19
8-20
8-20A
4-1
LIST OF ILLUSTRATIONS (cont'd)
Electrical
Components (Part 1 of 3)
- AO
Electrical Components (Part 2 of 3) -
AP
Electrical Components (Part 3 of 3)
- AQ
Print Head and Associated .
Tape Reader Assembly 68060125-5003
(Option)
Tape Reader Assembly 68060125-5002, (Option) (Alternate).
TABLES
306 Special Function
Note
Refer to the Engineering Change Notice
(ECN) sheets shipped with the printer
for changes made to the printer which
have not yet been incorporated into the
technical manual. Always keep these
Engineering Change Notice sheets with
the manual.
Note
Revision level indications at the lower
right-hand corner of a page reflect at
what revision of the manual that page was
updated.
-viii-
Page
8-39
8-41
8-43
8-45
8-47
8-49
4-8
Rev. E

SECTION 1
INTRODUCTION
This manual describes the Model 306 printer, manufactured by
Centronics Data Computer Corporation. It provides general information,
detailed theory of operation
and maintenance information enabling field
service personnel to service the printer. For serial input or other
detailed interface information, a separate
document for each interface
is published for your reference.
The manual is subdivided into eight sections, each with its
specific purpose.
Section 1 - INTRODUCTION, introduces the reader to the scope and
content of the manual, and provides the reader with
a general description of the
printer.
Section 2 - INSTALLATION, contains unpacking and installation in-
structions for the printer.
Section 3 - OPERATION, describes the use of all operator controls
and indicators.
Section 4 - THEORY OF OPERATION, contains a detailed description
of
each major operation performed by the printer
electronics, including flow charts, timing diagrams
and circuit diagrams.
Section 5 - REMOVAL, REPLACEMENT AND ADJUSTMENT PROCEDURES, in-
cludes step-by-step
removal and replacement procedures
for
all major assemblies and sub-assemblies in the
printer.
Section 6 - MAINTENANCE, includes electrical adjustments, preventive
maintenance procedures,
and a troubleshooting guide.
Section 7 - ELECTRICAL DRAWINGS AND LIST OF MATERIALS, contains a
complete set of schematic, wiring and component board
layout diagrams and their associated list of materials
for the
electrical portion of the printer.
Section 8 - MECHANICAL DRAWINGS AND PARTS LISTS, includes all printer
assembly drawings and their associated part lists for the
mechanical portion of the printer.
1-1

At the end of the manual are several appendices which include a
glossary of signal
mnemonics, standard 5 x 7 and optional 9 x 7 character
set, and parallel interface specifications.
1.1
GENERAL DESCRIPTION (Figure 1-1)
The Model 306 printer is a medium speed impact printer which uses
a standard 5 x 7 or optional 9 x 7 dot matrix for character generation.
Figure 1-1. MODEL 306 PRINTER (TOP AND VFU COVERS REMOVED)
The unit prints at a rate of 120 characters per second, which is
approximately one full 80-character line per second (including carriage
return time).
Paper is sprocket-fep, and paper widths from 4 inches to
9~ inches can be accommodated. The printer can produce one original and
four copies. Standard print format consists of 10 characters per inch
horizontally and 6 lines per inch vertically.
1.2 LOGIC FLOW DIAGRAM (Figure 1-2)
The standard printer contains an 80-character buffer. For serial
data inputs, optional
serial interfaces allow data to be received at
rates from 100 to 9600 baud. Several other optional interfaces are
available
as required by the user.
Once a line of printable characters is stored in the buffer, head
motion is initiated by activating the forward clutch, causing the print
head to move from left to right across the paper. With the head in motion,
data
is transmitted from the buffer to the character generator. From there,
character write pulses are sent to the driver
circuits, which energize
the
print head solenoids causing the print wires to form the characters on
the paper.
Rev. E 1-2

PARALLEL INPUT (TIMING)
M.,k - Binlty , - +2.410 !!U:; Vo!U
5p";l _ Bln.ty Q - 0 10 + 0.4 '0'011
O.'I~~
'~':'Sl ~ ~ ,"st"lo'
OI.IS.'Obl-U------U-
.t I-ISImlnl1
5oo1-151
m
.. J
~--l....:.-+-"""
RS 232 SERIAL INPUT (TIMING)
Blud A.'I -tOO - 9600
5'1" Puille - On. Bit Timl
StOP Puille - min. of ani Bit Tlml
M"k - Binlty , _ -3 to ·21 Voln
SPiel - Bin.,y 0 - +3 to +21 Voln
Figure 1-2. BASIC BLOCK DIAGRAM
Paper movement is initiated by a line feed, vertical tab and form
feed function. In the standard 306 printer, vertical form movement is soft-
ware controlled by means of line count pulses, rather than hardware-controlled.
However, an optional vertical format unit, (VFU) is available for
hardware-controlled vertical formatting, identical to the Series
100 printers.
In addition, the printer recognizes the following special control
codes:
bell, delete and elongated character, as described in Section 1.3.3.
1.3
PRINTER OPERATION
Basically, all printer functions can be grouped into one of the
following three categories:
1) character printing, 2) paper movement, and
3) other auxiliary functions such as bell, delete, etc.
1.3.1 CHARACTER PRINTING (Figures 1-3, 1-4)
A small aluminum carriage supports the print head assembly. During
printing operation, the carriage travels along the print line from left to
right. Printing is accomplished by selectively firing the print wires as
the print head moves from left to right across the print line. Printing
impulses energize the
print solenoids and drive the print wires against the
ribbon, paper
and platen to form the characters in a dot matrix pattern.
When the solenoids are de-energized, the wires are withdrawn so they are
flush with the surface of the jewel.
Each solenoid can fire independently
up to five times for anyone character. Figure 1-3 shows an example of the
dot matrix
forming the letter H. All character formation in the 5 x 7 and
9 x 7 dot matrix are shown in Series 300 Operators Manual.
1-3
Rev. F

JEWEL
'----A-~
Figure 1-3. PRINTING THE LETTER (H) Figure 1-4. PRINT HEAD COMPONENTS
The print head (Figure 1··4) consists of the jewel, casting and seven
solenoids with attached print wires. The seven print solenoids and their
attached print wires are arranged radially
around the print head. The free
ends of the print wires pass through a wire guide at the front of the print
head, which properly spaces the wires so that the correct wires pass through
the correct hole in the print jewel.
Printing action
is initiated when the input buffer has been filled
or a carriage return (CR) code has been received. The print head then sweeps
across the page until a CR command is decoded at the buffer output of the
head reaches the aO-column limit switch. At this time, the print head returns
to the
left margin and an automatic line feed is performed. As an option,
the automatic line
feed can be disabled. /'
1.3.2 PAPER MOVEMENT (Figure 1-5)
Paper can be moved manually by rotating the platen knob or auto-
matically
by any of three paper movement commands: line feed, vertical tab
and form feed.
Figure 1-5.
PAPER MOVEMENT MECHANISM
Rev. D

Power necessary to drive the sprocket-feed paper tractors controlling
paper movement, is transmitted from the main motor through an O-ring belt
to the
form feed mechanism, where it is then transferred via the paper drive
shaft to the paper tractors.
The form feed mechanism consists of a form feed
or release clutch, a line feed solenoid with slide unit, and a gear train
mechanically linking the
main motor to the paper feed tractors.
To initiate a single line feed, the line feed solenoid is energized
15 milliseconds. Upon completion of the line feed command, a 60-90 millisecond
delayed line
feed interval is generated. This allows the clutch pawl and
clutch mechanism to return home before another line feed is allowed.
Vertical forms movement is accomplished by applying a DC level to
the
paper feed solenoid. In the standard 306 printer, this paper movement
continues until it is either terminated by the reception of a delete code
(octal 177) or an INPUT PRIME signal at the interface connector, or a paper
time-out condition. However, if the optional Vertical Format Unit (VFU) is
used, the
paper movement is terminated when a hole is detected in the
appropriate
channel of the vertical format paper tape.
As paper moves in the printer, each line advance causes a line count
switch located in the
form feed mechanism to open and close. The two wires
from this switch go to the interface connector via the logic card. As a
result, a line count level from the input device is switched on and off by
the printer for each line advance. If the 306 contains no optional VFU,
the user's software can control vertical formatting by counting these line
count pulses
and terminating the paper movement operation when appropriate.
When the printer runs out of paper, a sensing switch activates a
two-second audible tone in a speaker (option) located at the rear. The
printer also stops printing and lights the PAPER EMPTY light on the control
panel.
1.3.3
SPECIAL FUNCTIONS
In addition to the printable characters shown in Appendix B, and
the carriage return, line feed, form feed, and vertical tab codes previously
described, the printer also recognizes the following special control codes.
Delete
(Octal 177) - Primes the printer electronics and clears the
buffer.
Bell (Octal 007) - With Bell option only -Generates a two-second
audible tone in the speaker at the front of the printer.
Select
(Octal 021) - Allows printer to receive data, same as
activating SELECT switch.
1-5
same
Rev. 0

Rev. E
1.4 SYSTEM FEATURES
1.4.1 SPECIFICATIONS SUMMARY
The Model 306 printer contains all the features described in the pre-
vious sub-sections of this
manual. Some of these features, in addition to a
few characteristics not previously mentioned, are summarized in the
following specifications.
Printing Method
Printing Rate -Characters
-Full Lines
~ Short Lines
Transmission Rate -Serial
-Parallel
Data Input
CharacterStructure
Code
Indicator-Switch Controls
Indicators
Manual Controls
Character Buffer
Format
PaperFeed
Paper
Number
of Copies
Dimensions
Weight
Electrical Requirements
Temperature -Operating
-Storage
Humidity -Operating
-Storage
Impact, character-by-character, one line at a time
120 characters per second
60 lines per minute (80 character line)
150 lines per minute (20-30 characters)
100 to 9600 baud (with Serial option)
See Timing Diagram, Appendix B
Parallel (Serial option available)
5 x 7 dot matrix, 10-pointtype equivalent
9 x 7 dot matrix, 10-point type equivalent (option)
USASCII- 64 characters printed
ON/OFF, SELECT, FORMS OVERRIDE.
Option. LINE FEED. TOP OF FORM
PAPER OUT, SELECT
Form ThiCkness, Paper Advance Knob
80 characters (1 line)
80 characters maximum per line, 6 lines per inch
Sprocket feed, adjustable to 91
/2" width
Standard sprocketed paper
Original and up to four carbon copies
12
3
//' high, 183 //' deep, 23
1
/4" wide
66 pounds
115 VAC ±10%,60 Hz.
115/230 VAC +10%,50 Hz (option)
40° to 100°F
-40° to 160°F
5% to 90% (no condensation)
0% to 95%
B. RIBBON SPECIFICATIONS
The printer uses a I-inch nylon ribbon mounted on 3-inch diameter
spools.
The following four colors are available:
Bl ack -Part No. 63002293-·5001
Red -Part No. 63002293-5002
Green -Part No. 63002293-5003
Blue -Part No. 63002293-5004
1-6

C. PAPER SPECIFICATIONS
The printer uses continuous form paper with standard feed holes on
each edge. Paper widths from 4 to 9~ inches can be accommodated by the
printer. Using multiple-part form, one original and up to 4 copies can be
printed, all very legible. Paper weight specifications are as follows:
Single-Part Forms: 15 to 20 lb
Multiple-Part Forms:
Original - 12 to 15 lb
Copies -9 to 12 lb, last copy 15 lb
(Maximum of five parts)
Carbon Paper:
1.4.2 STANDARD AND OPTIONAL FEATURES
standard features
• Parallel data input
• Elongated boldface characters (Iine-by-line)
•
Paper runaway inhibit (10 second time out)
• Lower case prints as upper case
• Automatic line feed on carriage return
" Gated strobe pulse (data input)
• 115 Volts, 60 Hertz
• Prints original plus four copies
• Coded character software
• Fixed vertical/horizontal registration
• Low noise level
• 5 x 7
Dot matrix
1.5 PHYSICAL DESCRIPTION
7~ lb with medium hardness
optional features
• Vertical format control
• Automatic motor control
• Additional sets of 64,96 or 128 characters
• 9 x 7 dot matrix character sets
Q Audio alarm buzzer
g 50 Hertz, 230 Volts AC
• Line feed switch
• Non-gated strobe
• Automatic line feed disabled
• Selectable sinQle Character elongation
• Automatic carriage return on line feed,
vertical tab and
form feed
• Serial communication interfaces
• Popular parallel computer interfaces
• Bottom of form
• Inhibit delete code
The printer is approximately 12" high by 19" deep by 23" wide, and
weighs approximately 66 pounds .. The complete printer is assembled on a base
made of cast aluminum. Enclosing the printer are three removable plastic
covers: the main cover, top cover and VFU cover. The top cover can be opened
to give access to the print head by tilting the cover back of lifting it
completely off. The VFU cover can also be tilted back or removed for access
to the optional Vertical Format Unit, if it is used.
Figures 1-6 to 1-9 are
different photographic views of the printer
taken with the covers removed. All major assemblies are identified, in
addition to a few other important components, the locations of which should be
noted. 1-7
Rev. D

1. Print Head Assembly
2. Video Ampl. and Cable Ass'y
3. Carriage
4.
Ribbon Cable
5. Damper Piston
6. Operator Panel
7. Damper Cylinder
8.
left Ribbon Feed
9. Vertical Format Unit Option
10. Pin Feed Mechan1sms
11. Paper Feed Shaft
12. Platen
13 . Platen Knob
14 . R1ght R1bbon Feed
Figure 1-6. LEFT FRONT VIEW OF 306
Rev. 0
1. Ha1n Dr1ve Motor
2. Dr1ve Mechan1sm
3. Forward Clutch
' 4. Reed Swftch (EOP)
5. Mafn Drfve Belt
6. T1m1ng Fence
7. Carr1age Return Spr1ng
8. Power Dr1ver Board
9. Optfcal Pfck-Up
10. l1ght Source
11. Optfc Bundle
12. Penetrat10n Control Knob
13. Form Feed Mechanfsm
14. Solenofd Ffnger Board
Figure 1-7. RIGHT FRONT VIEW OF 306
1-8

1. Logic/Power Supply Board
2. Logic/P.S. Fuses
7. AC Power Input
8. Input
Cable (W2)
3. AC and 35V Input Connector (JI) 9. Motor Control Option
4. DC Output Connector (J2) 10. Line Feed Solenoid
5. Input Connector 11. Line Count Switch
6. In-Line Fuse
Figure 1-8. REAR VIEW OF 306
1. 35V Power Supply
5. Paper Out Switch
2. Power Transformer 6. Main Printer Harness
3. DC Output Connector (J2)
4. AC and 35V Input Connector (J1)
7. Motor Starting Capacitor
Figure 1-9. REAR VIEW OF 306 (LOGIC/P.S. BOARD REMOVED)
Rev.D
1-9/1-10

SECTIONS 2 AND 3
INSTALLATION AND OPERATION
A separate Series 300 Operators Manual contains most of the in-
stallation, set-up and operating procedures for the Model 306 printer.
This Operators Manual should be referred to during normal printer in-
stallation and operation.
Included
on the following pages is additional information not
contained in the Operators Manual.
2.1 SITE PREPARATION (Figure 2-1)
A line drawing of the printer dimensions is shown in Figure 2-1.
I
12.82"
It-------r.
I·
11--------~""'"'-===--2J.17" HA,-===--~/I
WEIGHT: 615 POUNDS
Figure 2-1. PRINTER DIMENSIONS
Enviromental and electrical requirements at the installation
site are as follows:
Temperature:
Humidity (% RH):
Electrical:
40~ to 100
0 F (Operating)
-40 to 160
0 F (Storage)
5% to 90% (no condensation) -Operating
0% to 95% -Storage
115 VAC ±10% 60 Hz, 3 amps
115/230 VAC t10%, 50 Hz, 3 amps
2-1