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. and foreign patents, issued and pending. Information in this publication supercedes that in all previously published material. [. . . ] 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. [. . . ] Parts can be ordered through your local Tektronix field office. Changes to Tektronix instruments are sometimes made to accommodate improved components as they become available, and to provide benefit of the latest circuit improvements developed by our engineers. When ordering parts, include the following information: H Part number H Instrument type or model number H Instrument serial number H Instrument modification number (if applicable) Module Replacement The YT-1/YT-1S is serviced by replacing defective modules. There are three options you should consider: Module Exchange In some cases you may exchange the defective module for a re-manufactured module. [. . . ]