User manual TEKTRONIX YT-1S

Instruction Manual YT-1 / YT-1S Chart Recorder 070-6270-04 NOTE: This manual is intended for YT-1/YT-1S Chart Recorders serial numbers B030500 and higher, or units that have been upgraded to that level (to identify upgrade, see page 8-5 and note frame cutout next to print head). For instruments with serial numbers B030499 and lower that have not been upgraded, please contact your local Tektronix Customer Service Representative for information regarding module exchange service. First Printing: Oct. 1998 Copyright E Tektronix, Inc. 1998. All rights reserved. Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes that in all previously published material. Specifications and price change privileges reserved. Printed in the U.S.A. Tektronix, Inc., P.O. Box 1000, Wilsonville, OR 97070­1000 TEKTRONIX, TEK, and YT-1 / YT-1S are registered trademarks of Tektronix, Inc. WARRANTY Tektronix warrants that this product will be free from defects in materials and workmanship for a period of one (1) year from the date of shipment. If any such product proves defective during this warranty period, Tektronix, at its option, either will repair the defective product without charge for parts and labor, or will provide a replacement in exchange for the defective product. In order to obtain service under this warranty, Customer must notify Tektronix of the defect before the expiration of the warranty period and make suitable arrangements for the performance of service. Customer shall be responsible for packaging and shipping the defective product to the service center designated by Tektronix, with shipping charges prepaid. Tektronix shall pay for the return of the product to Customer if the shipment is to a location within the country in which the Tektronix service center is located. Customer shall be responsible for paying all shipping charges, duties, taxes, and any other charges for products returned to any other locations. This warranty shall not apply to any defect, failure, or damage caused by improper use or improper or inadequate maintenance and care. Tektronix shall not be obligated to furnish service under this warranty a) to repair damage resulting from attempts by personnel other than Tektronix representatives to install, repair, or service the product; b) to repair damage resulting from improper use or connection to incompatible equipment; or c) to service a product that has been modified or integrated with other products when the effect of such modification or integration increases the time or difficulty of servicing the product. THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THIS PRODUCT IN LIEU OF ANY OTHER WARRANTIES, EXPRESSED OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. TEKTRONIX' RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY. TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. Table of Contents General Safety Summary Operator Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Installation and Repacking Unpacking and Initial Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power Source and Power Requirements . . . . . . . . . . . . . . . . . . . . . . . Repacking for Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Operating Instructions Instructions for Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Paper Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General Information and Specifications Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Standards, Documents, and References Used . . . . . . . . . . . . . . . . . . . Characteristics and Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . Operator Performance Checks Head Alignment Chart Diagnostic and Chart Quality . . . . . . . . . . . . . Accessories and Options Standard and Optional Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Theory of Operations Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Circuit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Individual Write Command Operation . . . . . . . . . . . . . . . . . . . . . . . . . Individual Read Command Operation . . . . . . . . . . . . . . . . . . . . . . . . . Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interface Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calibration LCD Chart Diagnostic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Performance Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii viii ix ix ix 1-1 1-1 2-1 2-1 2-1 3-1 4-1 4-1 5-1 5-2 5-3 5-5 5-5 5-6 6-1 6-3 YT-1 / YT-1S Chart Recorder v Table of Contents Maintenance Required Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Part Removal/Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shipping Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Replaceable Parts Parts Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electrical Replaceable Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mechanical Replaceable Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exploded View Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 7-1 7-3 7-5 7-8 7-9 7-13 8-1 8-3 8-4 8-5 vi YT-1 / YT-1S Chart Recorder General Safety Summary CAUTION. Do not operate this product without paper installed, or, if operating when the paper runs out, shut the power off immediately. Printing without paper might burn out the printhead. Operator Safety Summary Power Sources This product is intended to operate from a power source supplied by the parent instrument. Do not attempt to power this module by any other means. Grounding the Instrument This product is grounded through the parent instrument. A protective ground connection is essential for safe operation. Danger Arising From Loss of Ground Upon loss of the protective-ground connection, all accessible conductive parts (including knobs and controls that appear to be insulating) can render an electric shock. Refer to connector changes to qualified service personnel. Do Not Operate in Explosive Atmospheres To avoid explosion, do not operate this product in an explosive atmosphere unless it has been specifically certified for such operation. YT-1 / YT-1S Chart Recorder vii General Safety Summary Do Not Remove Covers or Panels To avoid personal injury, do not remove the product covers or panels. Do not operate the product without the covers and panels properly installed. Service Safety Summary CAUTION. For qualified service personnel only. Refer also to the preceding Operator Safety Summary. Do Not Service Alone Do not perform internal service adjustment of this product unless another person capable of rendering first aid and resuscitation is present. Use Care When Servicing With Power On Dangerous voltages exist at several points in this product. To avoid personal injury, do not touch exposed connections and components while power is on. Disconnect power before removing protective panels, soldering, or replacing components. viii YT-1 / YT-1S Chart Recorder Installation and Repacking Unpacking and Initial Inspection Before unpacking the YT-1/YT-1S from its shipping container or carton, inspect for signs of external damage. If the carton is damaged, notify the carrier. The shipping carton contains the basic instrument and its standard accessories. Refer to the replaceable parts list for a complete listing. If the contents of the shipping container are incomplete, if there is mechanical damage or defect, or if the instrument does not meet operational check requirements, contact your local Tektronix Field Office or representative. If the shipping container is damaged, notify the carrier as well as Tektronix. The instrument was inspected both mechanically and electrically before shipment. It should be free of mechanical damage and meet or exceed all electrical specifications. Procedures to check operational performance are in the parent instruction service manual. Procedures to check electrical and mechanical specifications are in the Calibration section of this manual. Power Source and Power Requirements The YT-1/YT-1S is intended to be operated from the parent instrument's power supply. A protective ground connection by way of proper installation in the parent instrument is essential for safe operation. Further information on the YT-1/YT-1S power requirements can be found in the Operator Safety Summary and in the Operator section. Repacking for Shipment If the YT-1/YT-1S is to be shipped to a Tektronix Service Center for service or repair, attach a tag showing the name and address of the owner, name of the individual at your firm that can be contacted, complete serial number, and a description of the service required. If YT-1 / YT-1S Chart Recorder ix Installation and Repacking the original packaging is unfit for use or is not available, repackage the instrument per the instructions near the end of the Maintenance section in this manual. x YT-1 / YT-1S Chart Recorder Operating Instructions Operating Instructions Instructions for Use Making permanent records with the 1500-Series is easy with the Tektronix YT-1/YT1-1S Digital Chart Recorder. CAUTION. Do not operate this product without paper installed, or, if operating when the paper runs out, shut the power off immediately. Printing without paper might burn out the printhead. 1. Make sure the desired waveform (or waveforms) is displayed on the LCD. 2. Slide back the protective cover on the recorder. Push PRINT on the front panel of the chart recorder. 3. When the chart recorder has finished, tear off the paper recording, pulling the paper to the left. You may prefer to close the door prior to tearing off the chart to facilitate a cleaner tear. Making chart recordings with the YT-1/YT1-1S will reduce the charge of the battery pack (if so equipped) in the parent instrument. Read the appropriate battery information in the parent instrument Operator section. Paper Replacement 1. Turn the knurled knob on the front panel of the chart recorder counter-clockwise until it loosens. Pull the unit from the parent instrument. Set the YT-1/YT1-1S with the front panel to the right. 2. With your thumbs, push the frame surrounding the motor pulley. Push until the motor assembly latch locks the motor assembly to the side frame. This loosens the tension in the paper path, allowing any remaining paper to be removed. 3. Remove the paper retaining knob. Remove any paper and the empty paper core. YT-1 / YT-1S Chart Recorder 1­1 Operating Instructions 4. Following the diagram on the top of the recorder, place a fresh roll of paper in the recorder so the paper unwinds off the right side of the roll into the paper path (looking down on the recorder, the paper unrolls clockwise). Tearing the end of the paper roll on a slant will facilitate placing the paper in the slot. 5. Assure that the paper drops down into the paper path without binding, and the paper protrudes through the slot in the front of the instrument. Release the keeper from the frame, and the paper drive mechanism will return to the operating position. 1­2 YT-1 / YT-1S Chart Recorder General Information and Specifications General Information and Specifications Product Description The Tektronix YT-1/YT-1S Chart Recorder is an optional accessory for a parent instrument (e.g., the 1500B/C-series Metallic Time Domain Reflectometers). It is designed to plug into the instrument in the option port. The YT-1/YT-1S has a water resistant door that covers the record paper slot. A chart recording is a permanent record. It can be of great service in fault interpretation (e.g., a chart recording of a fault can be compared to that of an acceptable test). Standards, Documents, and References Used Terminology used in this manual is in accordance with industry practice. Abbreviations are in accordance with ANSI Y1.1-1972, with exceptions and additions explained in parentheses in the test. Graphic symbology is based on ANSI Y32.2-1975. Logic symbology is based on ANSI Y32.14-1973 and manufacturer's data books or sheets. A copy of ANSI standards may be obtained from the Institute of Electrical and Electronic Engineers, 345 47th Street, New York, NY 10017. Characteristics and Specifications The tables on the following pages list the electrica characteristics and features that apply to the Tektronix YT-1/YT-1S Chart Recorder when it is installed in a Tektronix 1500B/C-series TDR instrument and after a 20 minute warm-up. The Performance Requirement column describes the limits of the characteristic and Supplemental Information column describes features and typical values or information that might be helpful. YT-1 / YT-1S Chart Recorder 2­1 General Information and Specifications Printing Specifications Characteristic Writing method Chart paper Performance Required Roll type, 50mm. Outside dia. 50mm max. Accept 15mm spindle. Thermal coating facing inside roll. Will allow recorder to meet print density spec. Shall be marked by a red line beginning 5 ft. from the end of the roll. Black Solid black print pattern shall measure at 1.1D on Kodak Gray Scale. Supplemental Infor. Direct thermal Example: See Tektronix part number in Accessories section. End-of-roll warning Print color Print density Pattern created by printing 40 element blocks three times each until a 360 bit wide by at least 200 bit long (45mm by 25mm min.) image is formed. Density measurement made with an appropriate Densitometer. Patten print at 25°C ± 5°C. Background den- Less than 0.2 D when sity stored at 70°C for 24 hours. Print drop-outs No more than 1% of the elements to be printed shall fail to print. Adjacent failures shall number three or less. 0.125mm Print element width Addressable print 384 (48 8-bit bytes) elements Print field width 48mm Alignment of print Entire print field must lie on field paper. 2­2 YT-1 / YT-1S Chart Recorder General Information and Specifications Characteristic Orthogonality of print field Performance Required A line printed across the paper shall be perpendicular to the edge of the paper within 1.0 degrees. Supplemental Infor. Paper movement 0.125mm, ± 0.01mm per ADVANCE command Record length Print time 10.87 to 12.76 inches Algorithm dependent Typical 20 seconds Algorithm dependent. Power Specifications Characteristic +5 Volts +16 Volts Performance Required +5V ± 5%, 500mW max +16 Volts ± 10%. Average Power = 12W max. Peak current not to exceed 1.7A. Supplemental Infor. Power is applied to recorder only while it is operating. Mechanical Characteristics: YT-1/YT-1S plugs into the parent instrument Option Port. YT-1 / YT-1S Chart Recorder 2­3 General Information and Specifications Environmental Specifications: Apply when chart recorder is properly installed in a 1500B/C-series TDR Option Port. Temperature: Operating Non-operating Humidity: Operating Non-operating Altitude Operating Non-operating Vibration ­10°C to +55°C ­62°C to +85°C Prolonged exposure to temperatures above 70°C might cause thermal paper to darken. 0 to 100% RH, excluding condensing 0 to 100% RH, including condensation To 15,000 ft above sea level To 40,000 ft above sea level 5 to 15Hz, 0.7g MIL-T-28800C 15 to 25Hz, 1.3g 25 to 55Hz, 3.0g 30g, 11ms 1/2 sine waveform three shocks in each direction on each axis. 48 hours, 20% solution. Per MIL-T-28800C. When operated in host instrument, unit meets the following requirements of MIL-STD-461A: CE02, CE04, CS02, CS06, RE02, RE02.1, RS03, RS03.1. 3kV to 20kV, Tekronix standard 062­2862­XX Splash-proof and drip-proof Shock or vibration greater than1g may cause temporary trace discontinuity. Shock Salt atmosphere Electromagnetic compatibility Electrostatic discharge Water resistance 2­4 YT-1 / YT-1S Chart Recorder Operator Performance Checks Operator Performance Checks The following checks will confirm if the YT-1/YT-1S is operating according to specification. They are found in the Chart Diagnostics Menu in the Diagnostics Menu of the parent instrument. Head Alignment Chart Diagnostic This test gives the chart recorder a rapid feed test as well as a test for print dropouts, feed spacing, and alignment of the head. If the YT-1/YT-1S is not operating properly, symptoms may include pixel drop-out, washed-out print, ``titled'' chart, chart off the page, or improper or erratic speed. Chart Quality 1. Access the Head Alignment chart in the Chart Diagnostics menu located under the Diagnostics Menu of the parent instrument. 2. Press MENU. The diagnostic chart that is printed should look like the figure below and must meet the following criteria: SOLID LINES Equally Spaced Narrow Lines 6 Inches 12 INCHES Equally Spaced Wide Lines 6 Inches a. The total chart from first printed line to last printed line must measure between 10.87 to 12.76 inches. YT-1 / YT-1S Chart Recorder 3­1 Operator Performance Checks b. There must be between 5.43 to 6.38 inches of narrow spaced lines on the chart. c. There must be between 5.43 to 6.38 inches of wide spaced lines on the chart. d. Fold the paper in half at the last narrow line. The two halves of the chart should be equal in length. e. The entire diagnostic should be printed within the boundaries of the paper. f. All vertical lines should be perpendicular relative to the top and bottom of the chart within 1°. g. The three solid vertical lines on the chart must be complete with no missing dots. h. All lines on the chart must be legible with no fading, smearing, or irregularities in print blackness. If your test chart does not meet the above criteria, send your chart recorder and include the test chart. 3­2 YT-1 / YT-1S Chart Recorder Accessories and Options Accessories and Options Standard Accessories Accessory Chart paper, single roll Tektronix Part Number 006­7647­00 Optional Accessories Accessory Chart paper, 25­roll quantity Chart paper, 100­roll quantity Tektronix Part Number 006­7677­00 006­7681­00 Options There are no options for the YT-1/YT-1S Chart Recorder YT-1 / YT-1S Chart Recorder 4­1 Accessories and Options 4­2 YT-1 / YT-1S Chart Recorder WARNING The following servicing instructions are for use only by qualified personnel. To avoid injury, do not perform any servicing other than that stated in the operating instructions unless you are qualified to do so. Refer to all safety summaries before performing any service. Theory of Operations Theory of Operations Introduction The YT-1/YT-1S Chart Recorder is to be used with a parent instrument, such as the 1502B/C or 1503B/C Time Domain Reflectometer. This manual contains information on the YT-1/YT-1S only. For related information on the parent instrument, see Option Port Interface in the Circuit Description section of respective service manual. The YT-1/YT-1S consists of a drive motor assembly, a thermal printhead, and an electronic circuit board. More information can be found in the Specification section of this manual. A block diagram of the Option Port can be found in the parent manual in the Circuit Description section. See the following figure for the block diagram of the YT-1/YT-1S Chart Recorder. Controller Board Motor Control 1 Address and Control 3 Decode and Control 1 Data Latch 4 Power and Ground Interrupt Switch Status Power and Ground 1 1 Serial Word Load 1 1 7 J2 2 3 2 4 J3 Motor Assembly Drive Motor To Option Port J1 1 6 6 8 Data YT-1 / YT-1S Chart Recorder Printhead Control Thermal Print Assembly Thermal Printhead 5­1 Theory of Operations Circuit Description Bit Map (Data Matrix) Operation Bit-Map Description Bit­map operation permits the host to control the 384 individual bits (48 bytes) that make up the recorder print field. This allows any combination of dots to be printed including alpha-numerical characters and graphics. All print data should be sent in the form of bytes (1 byte = 8 bits). The state of the dots printed is controlled by the state of the data bits sent by the host to the recorder. A ``0'' will turn an element off and a ``1'' will turn an element on when a row is printed. The bit-mapping is done on rows of the page. There are 8 rows per millimeter and 48 bytes per row. The resolution is thus 1/8mm across the page. Bit-Map Operation The recorder uses a thermal printhead with 384 individual elements (48 bytes). The bytes of digital data are shifted through the printhead from left to right. As the new bytes of data are shifted in by the host, the old bytes remaining from the previous line of print data are shifted out one by one. To replace all the old data bytes with new ones the host must completely refill the printhead each time a new line is to be printed. If the host does not completely refill the printhead with a new line of data before printing, the remaining old data will be printed out with the new data. The new data will also be shifted to the left of its proper print field. The host should never attempt to turn on more than 25% of the dots in the print field at one time. If the host's desired pattern requires the energizing of more that 25% of the dots on a single line, the solution is to divide the pattern into smaller parts. These smaller parts can then be loaded and printed one at a time until the complete pattern is printed. The host can then move on to the next line of print data by advancing the paper. Bits will be turned on as shown: 5­2 YT-1 / YT-1S Chart Recorder Theory of Operations Direction of Paper Travel BYTE 1 on this side Host usable print field 48 bytes wide BYTE 48 on this side Thermal Printhead Thermal Paper Printed side of paper Individual Write Command Operation Load a Byte of Print Data When this write command operation is used the recorder will take the data byte (8 bits) that the host has placed on the data bus and shift it out to the recorder printhead. This command should only be used when the recorder is ready to accept data (i.e. the Accept Data status line D5 = 1). Use of this command will cause the Accept Data status line to be disabled (D5 = 0). This status line will not be re-enabled until the recorder is ready to accept another data byte. No byte should be sent until this line goes high again (D5 = 1). Latch a Line of Print Data This write command operation should precede the print command. When the host has completely finished loading the printhead with data this command is used to latch that data into the printhead so that it can be printed. This command should only be used when the recorder is not printing or shifting data (i.e., both Print Ready and Accept Data status lines are high D6 = 1, D5 = 1). Sending this command while either of these status line is disabled could cause faulty data to be printed out. YT-1 / YT-1S Chart Recorder 5­3 Theory of Operations Print a Line of Data This write operation causes the line of print data that the host has loaded and latched into the printhead to be printed. This command should only be used when the recorder is ready to print (i.e., the Print Ready status line D6 = 1). This host should never attempt to turn on more that 25% of the dots in the print field at one time. If the host's desired pattern requires the energizing of more than 25% of the dots on a single line, the solution is to divide the pattern into smaller parts. These smaller parts can then be loaded and printed one at a time until the complete pattern is printed. The host can then move on to the next line to print data by advancing the paper. Advance Paper One Line This write command operation causes the recorder to advance the paper one line (1/8mm). This command can be used after printing to move to the next print line or can be used without having printed to create a blank line or print leader. This command should only be used when the recorder is ready to advance (i.e., the Advance Ready status line D4 = 1). Sending this command while the status line is disabled will disrupt the recorder's stepper motor and cause erratic motor action to result. Print a Line and Advance Paper One Line This write command operation combines the print and advance commands previously discussed. Upon receiving this command the recorder will print the current line of print data and advance the paper to the next line. This command should only be used when the recorder is not printing or advancing the paper (i.e., both Print Ready and Advance Ready status lines are high D6 = 1, D4 = 1). Sending this command before the recorder is ready could cause printing errors or erratic motor action. Reset Recorder to Quiescent State This write command resets the recorder to a quiescent state waiting for the host to send a command. After reset the host should still check the status lines before sending a command to insure the recorder is ready. 5­4 YT-1 / YT-1S Chart Recorder Theory of Operations Individual Read Command Operation Read Recorder Identify Code This read command operation allows the host to identify the recorder and insure that it is properly inserted into the host unit. The recorder has an identify code of (01H). Read Recorder Status Codes This read command operation allows the host to insure that the recorder is ready to accept the desired command. The host must always wait until the recorder is ready before sending a command. By checking the corresponding status line or lines the host can determine recorder readiness. There are status lines for Ready to Print (D6), Ready to Advance (D4), Ready to Accept Data (D5), and Recorder Fault (D7). Only send commands when the recorder is ready. Protocol Introduction This protocol is designed for the Tektronix YT-1/YT-1S bit map only thermal dot matrix recorder. The Tektronix YT-1/YT-1S chart recorder produces a hard copy record on thermally activated paper of data provided through a parallel digital interface. The bit map (dot matrix) data is provided one byte at a time (1 byte = 8 bits) line by line (1 print line = 48 bits). This allows any combination of dots to be printed including alpha-numeric characters and graphics. Each dot corresponds to one element of a thermal printhead with a resolution of 200 dots per inch (8 dots per mm). Printing is achieved by energizing the individual elements of the printhead. YT-1 / YT-1S Chart Recorder 5­5 Theory of Operations Interface Information The YT-1/YT-1S chart recorder communicates to the host system via the host's address and data bus. The interface includes four address lines, eight data lines, one interrupt line, and three control lines. All interface lines are 74HC compatible. Inputs and Outputs The following signal descriptions apply to the host-to-recorder interface. Refer to the following table for pin designations (see Interface Pin Structure). A0 ­ A3 (INPUT): D0 ­ D7 (INPUT): (INPUT): (INPUT): (INPUT): (OUTPUT): Address lines from the host for the read and write operations to the recorder (all lines active high). Bidirectional data lines for the read and write operations to the recorder (all lines active high). Recorder select line from the host (active low). Data read line from the host (active low). Data write line from the host (active low). Interrupt request line from the recorder (active low). Interface Pin Structure The interface pin structure table along with the associated waveforms are in the Maintenance section of this manual. A 25-pin male D-shell connector is used on the recorder. Information about the operation of these pins is available under Option Port Interface in the Circuit Description section of the 1502B and 1503B Service manuals. 5­6 YT-1 / YT-1S Chart Recorder Theory of Operations Interface Characteristics Characteristic Connector Performance Required 25-pin male D-shell (Holmberg HYM25A28AP or equiv.) As defined under heading: Protocol 74HC CMAS or equiv. Ground Closure on IR 2.5ms typical. Measure from time command sent to time BUSY flag clears. 4ms typical < 5µs typical < 5µs typical Supplemental Info Protocol Logic Interface Print Initiation Command Execution Times Print Command Advance Load Data Byte Latch Printhead Data IR = Pin 7 General Interrupt Operations The recorder generates an interrupt request (IR) each time the record push button is depressed. This signal is active low. This signal does not disable communication between the host and the recorder, thus allowing read and write operations to continue even though an interrupt request has been received. General Command Operations All commands are sent from the host to the recorder over the address interface bus (A0 - A3). All commands are accompanied by a low strobe of the recorder select line from the host (RS). All read commands are accompanied by a low strobe of the data read line from the host (RD). All write commands are accompanied by a low strobe at the date write line from the host (WR). YT-1 / YT-1S Chart Recorder 5­7 Theory of Operations Read Command Operations The recorder has the following read command operations: Address 0H Address 1H Address 2H ­ FH Identify code for recorder (Recorder = 01H) Status codes for recorder Not used by recorder The status code bits are formatted as follows: D0 ­ D3 D4 D6 D7 Not used by recorder Indicates recorder ready to accept advance command; 0 = Recorder not ready 1 Indicates recorder ready to accept print command; 0 = Recorder not ready 0 Indicates recorder fault exists; 1 = No fault exists Write Command Operations The recorder has the following write command operations: Address 0H Address 1H Address 2H Address 3H Address 4H Address 5H Address 6H ­ FH Reset recorder to quiescent state Advance paper one line with no printing Load a byte of print data (8 bits) Latch a line of print data Print a line and advance the paper one line Print a line with no advance of paper Not used by recorder 5­8 YT-1 / YT-1S Chart Recorder Calibration Calibration The YT-1/YT-1S Chart Recorder has no electrical adjustments, and few mechanical adjustments. Since the mechanical adjustments are done at the factory, they are not included in the Calibration section. The mechanical adjustments can be found in the Maintenance section. The Performance Check will determine whether or not the instrument is operating according to published specifications. The YT-1/YT-1S Chart Recorder Performance Check is accomplished via a diagnostic test on the parent instrument (1500B/C-series) LCD Chart Diagnostic Technically this is not a diagnostic, but for assistance in troubleshooting, temporary adjust of the printing characteristics, and a back-up for the PRINT push button. For information on the troubleshooting aspects of LCD Chart, see the Maintenance section of this manual. The printing characteristics of the YT-1/YT-1S are designed to provide chart recordings in environmental extremes under varying conditions. If it does become necessary to change the chart characteristics, it is possible from the front panel of the 1500B/C-series instrument. The thermal printhead of the YT-1/YT-1S has 384 print elements. Because of power economy, not all of the elements are turned on at the same time. When printing, only 40 elements (or dots) of the printhead are activated at a time. Forty dots equals a segment. If it is intended to make the dots darker, elements can be turned on more than once, analogous to a ``double-strike'' on a mechanical printer. 1. Using MENU and POSITION, access LCD chart in the Chart Diagnostics menu. YT-1 / YT-1S Chart Recorder 6­1 Calibration ac O F F O F F O F F 0.00 ft auto 2. When adjusted, the left Vp knob will adjust the number of dots the YT-1/YT-1S will print per segment, ranging from 13 to 41. The effect of this adjustment is subtle. 3. When adjusted, the right Vp knob will adjust the number of prints or ``strikes'' per segment. This adjustment is quite dramatic, resulting in a much darker or lighter chart, and a corresponding change in printer speed. 0.00 ft ac O F F O F F O F F auto When the parent instrument POWER is turned on, the printing characteristics will default to 40 elements per segment and one print per segment. 6­2 YT-1 / YT-1S Chart Recorder Calibration This diagnostic also takes the place of the PRINT push button. If the button should become defective, simply run the LCD chart diagnostic and current screen will be printed. Paper Skew If the paper tends to run up to the top or down to the bottom of the paper exit slot of the recorder, the paper skew may need adjustment. Symptoms include information printed off the top or bottom of the page and paper jamming. Occasionally the paper may skew after the paper has been replaced. This is due to improper setting of the paper in the feed path. This will usually clear itself after a couple of charts. If it does not, the paper still skews after a minimum of two charts, the paper guide would be adjusted. If the YT-1/YT-1S did not pass the Head Alignment Chart diagnostic, refer to the Maintenance section of this manual. Performance Check The following checks will confirm if the YT-1/YT-1S is operating according to specification. They are found under ``Chart Diagnostics Menu'' in the ``Diagnostics Menu''. Head Alignment Chart Diagnostic This test gives the chart recorder a rapid feed test as well as a test for print dropouts, feed spacing, and alignment of the head. If the YT-1/YT-1S is not operating properly, symptoms may include pixel drop-out, washed-out print, ``tilted'' chart, chart off the page, or improper or erratic speed. Chart Quality 1. Access Head Alignment chart in the Chart Diagnostics menu located under Diagnostics Menu of the parent instrument. 2. Press MENU. The diagnostic chart that is printed must meet these criteria: YT-1 / YT-1S Chart Recorder 6­3 Calibration a. The total chart from first printed line to last printed line must measure between 10.87 to 12.76 inches. b. There must be between 5.43 to 6.38 inches of narrow spaced lines on the chart. c. There must be between 5.43 to 6.38 inches of wide spaced lines on the chart. d. Fold the paper in half at the last narrow line. The two halves of the chart should be equal in length. e. The entire diagnostic should be printed within the boundaries of the paper. f. All vertical lines should be perpendicular relative to the top and bottom of the chart within 1 degree. g. The three solid vertical lines on the chart must be complete with no missing dots. h. All lines on the chart must be legible with no fading, smearing, or irregularities in print blackness. SOLID LINES Equally Spaced Narrow Lines 6 Inches 12 INCHES Equally Spaced Wide Lines 6 Inches 6­4 YT-1 / YT-1S Chart Recorder Maintenance Maintenance This section contains information of preventive and corrective maintenance, troubleshooting, and shipping instructions. CAUTION. We recommend that service be performed at an authorized Tektronix Service Center, or by a technician skilled in digital sampling techniques. The circuit board has SMT devices that require special equipment to replace. If found defective, we recommend that the ECB be replaced as an entire unit. We have included a majorparts/connectors locator as an aid to assist in troubleshooting. Required Tools This is a list of common tools needed to accomplish the maintenance procedures that follow. Oscilloscope (Tektronix 5440 or equivalent) Option Port extension cable (174­0950­00) 3/8 inch hex nutdriver 1/2 inch hex nutdriver 0.050 hex wrench Phillips head screwdriver Straight blade screwdriver Long-nosed pliers Cotton swabs Preventive Maintenance Preventive maintenance includes cleaning and visual inspection. A convenient time to perform preventive maintenance is during the periodic performance check/calibration procedure. If the instrument has been subjected to extreme environments or harsh handling, more frequent preventive maintenance may be necessary. YT-1 / YT-1S Chart Recorder 7­1 Maintenance Cleaning CAUTION. Do not use chemical cleaning agents that contain benzene, toluene, xylene, acetone, etc., because of possible damage to plastics in the instrument. The outside chassis and front panel should be cleaned gently with a damp cloth. The interior of the YT-1/YT-1S is protected from dirt and dust as long as it is installed in the option port and the print door is closed. However, if interior cleaning is necessary, blow off accumulated dust with low-pressure air, and remove remaining dirt with a soft brush, cotton swab or pipe cleaner moistened with isopropyl alcohol. The paper must be removed before cleaning with alcohol. The thermal printhead can be cleaned with a soft cotton swab dipped in a little alcohol. Latch the motor assembly out of the way, remove the paper, and carefully clean the printhead by swabbing the surface. Any of the surfaces that are in the paper path should also be cleaned. Lubrication No lubrication is necessary. It is recommended, however, that the YT-1/YT-1S be cleaned on a regular basis. Visual Inspection Obvious defects such as broken connectors, damaged board, frayed cables, improperly seated components and heat-damaged components should be corrected first before attempting further troubleshooting. Heat damage usually indicates a deeper problem somewhere in the circuitry, and should be traced and corrected immediately. We do not recommend electrical checks of individual components because defective components will become evident during instrument operation. 7­2 YT-1 / YT-1S Chart Recorder