Epson tm u950 error 3

technical manual

TM-U950/TM-U950P

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, mechanical, photocopying, recording, or otherwise, without the prior written permission of Seiko Epson Corporation. No patent liability is assumed with respect to the use of the information contained herein. While every precaution has been taken in the preparation of this book, Seiko Epson Corporation assumes no responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the information contained herein.

Neither Seiko Epson Corporation nor its affiliates shall be liable to the purchaser of this product or third parties for damages, losses, costs, or expenses incurred by purchaser or third parties as a result of: accident, misuse, or abuse of this product or unauthorized modifications, repairs, or alterations to this product, or (excluding the U.S.) failure to strictly comply with Seiko Epson Corporation’s operating and maintenance instructions.

Seiko Epson Corporation shall not be liable against any damages or problems arising from the use of any options or any consumable products other than those designated as Original Epson Products or Epson Approved Products by Seiko Epson Corporation.

EPSON and ESC/POS are registered trademarks of Seiko Epson Corporation.

NOTICE: The contents of this manual are subject to change without notice.

TM-U950/TM-U950P Technical Manual

FCC CLASS A

FCC Compliance Statement

For American Users

This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment.

This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference, in which case the user will be required to correct the interference at his own expense.

WARNING

The connection of a non-shielded printer interface cable to this printer will invalidate the FCC Verification of this device and may cause interference levels which exceed the limits established by the FCC for this equipment.

You are cautioned that changes or modifications not expressly approved by the party responsible for compliance could void your authority to operate the equipment.

FOR CANADIAN USERS

This digital apparatus does not exceed the Class A limits for radio noise emissions from digital apparatus as set out in the radio interference regulations of the Canadian Department of Communications.

Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites applicables aux appareils numériques de Class A prescrites dans le règlement sur le brouillage radioélectrique édicté par le Ministère des Communications du Canada.

GEREÄUSCHPEGEL

Gemäß der Dritten Verordrung zum Gerätesicherheitsgecsetz (Maschinenlärminformations- Verordnung-3. GSGV) ist der arbeitsplatzbezogene Geräusch-Emissionswert kleiner als 70 dB(A) (basierend auf ISO 7779).

Introduction

The TM-U950 printer is an ESC/POS® compatible high-performance point of sale (POS) printer which can handle receipt, journal, and slip paper. There are two models: the TM-U950 and the TM-U950P. The TM-U950P has a parallel interface. Differences between the two models are noted throughout this manual.

The main features of the TM-U950 and TM-U950P printers are the following:

Usable with a wide range of slip paper types.

Non-protruding interface connectors integrated in the body of the printer.

Bidirectional logic seek for high throughput.

Paper feed pitch of 1/144 inch.

Integrated printer buffer with 32 byte or 2 KB capacity.

Slip paper eject sensor.

ASB (Automatic Status Back) function to send the printer status automatically.

EPSON intelligent module connection (Not available on the TM-U950P).

EPSON customer display series connection (Not available on the TM-U950P).

Optional Magnetic Ink Character Recognition (MICR) reader that enables the printer to perform consecutive reading and processing of MICR characters and printing endorsements (not available for the TM-U950P).

TM-U950/TM-U950P Technical Manual

About This Manual

Chapter 1 provides general specifications and hardware configuration information.

Chapter 2 provides general operating principles and printer mechanism configuration information.

Chapter 3 provides handling and maintenance information.

Chapter 4 provides troubleshooting information.

Chapter 5 provides printer disassembly, assembly, and adjustment instructions.

Chapter 6 (Appendix) provides circuit board and exploded diagrams.

Notes and Cautions

Note:

Notes have important information and useful tips on the operation of your printer.

CAUTION:

Cautions must be observed to avoid damage to your equipment.

Revision Sheet

Rev. A

TM-U950/TM-U950P Technical Manual

Contents

Chapter 1 Features and General Specifications

Chapter 3 Handling and Maintenance

TM-U950/TM-U950P Technical Manual

TM-U950/U950P Technical Manual

Chapter 1

Features and General Specifications

Features

The TM-U950 printer is an ESC/POS™ compatible high-performance point of sale (POS) printer which can handle receipt, journal, and slip paper. There are two models: the TM-U950 and the TM-U950P. The TM-U950P has a parallel interface. Differences between the two models are noted throughout this manual.

The main features of the TM-U950 and TM-U950P printers are the following:

Usable with a wide range of slip paper types.

Non-protruding interface connectors integrated in the body of the printer.

Bidirectional logic seek for high throughput.

Paper feed pitch of 1/144 inch.

Integrated printer buffer with 32 byte or 2 KB capacity.

Slip paper eject sensor.

ASB (Automatic Status Back) function to send the printer status automatically.

EPSON intelligent module connection (Not available on the TM-U950P).

EPSON customer display series connection (Not available on the TM-U950P).

Optional Magnetic Ink Character Recognition (MICR) reader that enables the printer to perform consecutive reading and processing of MICR characters and printing endorsements (not available for the TM-U950P).

TM-U950/U950P Technical Manual

General Specifications

Printing Specifications

Operation principle

Serial impact dot-matrix printer

Print head wire layout

Serial 9-pin

Dot pitch

0.353 mm (1/72”)

Dot wire diameter

0.29 mm (.01”)

Figure 1-2. Dot Configuration

Print direction

Bidirectional logic seek

Print width (printable area)

Paper roll: 61.1 mm (2.41”)

Slip paper: 135.6 mm (5.34”)

Paper feed pitch

4.233 mm (1/6”) (default setting) adjustable (by commands) in 1/144-inch steps

Paper feed principle

Friction feed

Paper feed rate

Approx. 3.4 IPS (continuous paper); 60.3 ms per line (1/6-inch paper feed)

Printing format

See CPI in Table 1-2.

Character spacing

See Table 1-2.

Total dot count

As shown in the table below, the TM-U950 has three printing modes, which differ in printing speed and head power time (impact).

Table 1-1. Printing Operation Mode

Character Specifications

Character set

Character matrix

(Alphanumeric, international, extended graphics) 7 x 9 (spacing: 2 half-dots)

0 x 9 (spacing: 3 half-dots)

Larger spacing can be set by using ESC SP.

Table 1-2. CPI, CPS, CPL, Character Size

TM-U950/U950P Technical Manual

Figure 1-3. Character Size

Paper Specifications

Paper type

Paper roll

Wood-free paper (single layer only)

Slip paper

Plain paper Carbon copy paper

Pressure-sensitive paper

Paper dimensions

Temperature and copying capability

As copying capability is influenced by the ambient temperature, printing must be performed under the conditions described in Table 1-3.

Table 1-3. Relationship Between Ambient Temperature and Number of Copies

Paper thickness and copying capability

Carbon copy paper (original + 4 copies)

0.36mm (.014”) or less (1 + 4)

Pressure-sensitive paper (original + 4 copies)

Note:

When using multi-ply paper that consists of an original and three copies, be sure to print with a 9 x 9 font. If a 7 x 9 font is used, some characters on some of the copies may not be readable.

Check paper (only when the printer is used with the MICR reader)

Notes on setting the print operation mode

The GS E command sets print mode (printing speed and print head energizing time).

When the power is turned on, normal mode is selected as the default. The printer automatically switches from normal mode to copy mode when slip is selected by ESC c 0.

Notes on slip paper

The slip paper must be flat, without curls or wrinkles, especially at the top edges. Otherwise, the paper may rub against the ribbon and become dirty.

There must be no glue on the bottom edge of slip paper. It is desirable for the glue to be on the top edge. Choose slip paper carefully when the glue is on the right or left edge, since paper feeding and insertion are affected by gluing conditions (e.g., glue quality, method, and length) and glue location (see Figure 1-4). Be especially careful when slip paper is wide and has the glue on the right or left edge, since meandering may occur.

Since the slip insertion sensor uses a photo sensor, paper that has holes at the sensor position, or is translucent, must not be used (see Figure 1-5).

Since the slip ejection sensor uses a reflective photo sensor, paper that has holes or dark portions with low reflection (less than 40% reflection) at the sensor position must not be used (see Figure 1-6).

Be sure to perform slip printing with a paper roll loaded to avoid incorrect paper feeding due to paper jams.

Use thinner paper (N30 or equivalent) between the top and bottom sheets of multi-ply paper. If thick paper is used, the copy capability is lowered.

Notes on using personal check paper (for printers with an MICR reader)

The personal checks must be flat, without curls, folds, or wrinkles (especially at the edges). Otherwise, the check may rub against the ribbon and become ink-stained.

Figure 1-4. Slip Paper Glued Area

Figure 1-5. Slip Insertion Sensor Position

Figure 1-6. Paper Holes and Low Reflection Prohibited Area

Print area

Paper roll

Figure 1-7. Paper Roll Print Area

TM-U950/U950P Technical Manual

Slip paper

Figure 1-8. Slip Paper Print Area

*Note

When the printer uses an MICR reader, this width is 5.0mm (0.20”).

Paper Roll Feed Mechanism

Feed principle

Drop-in loading

Paper roll near-end detection

Separate sensors for receipt paper and journal paper.

Journal Paper Take-up Mechanism

Automatic take-up by journal paper feed motor.

Auto-cutter

Auto-cutter is installed only on receipt side, for full and partial cuts.

Electrical Specifications

Printer operation voltage (using supplied AC adapter)

+24 V DC ± 10%

Ripple voltage: 300 mVpp or less (only when the printer is used with the MICR reader)

Current consumption

During printing

Average approx. 1.8 A

(R/J, α — N, 40-character printing) Peak approx. 8 A

During slip paper feed to printing position: Average approx. 0.3 A (for approx. 1.4s)

During standby Average approx. 0.3 A

Operating MICR reader

(when the printer used with the MICR reader) Mean — approximately 2.3 A

(Approximately 1.4 seconds)

Stamp

Stamp mechanism is available as a factory option for the receipt side.

Dimensions of stamp pad: See Figure 1-9.

Dimensions of stamp set: See Figure 1-10.

[Unit: mm]

Ink Ribbon

Ribbon cassette

ERC-31 (P)

ERC-31 (B)

Color

Purple: ERC-31 (P)

Black: ERC-31 (B)

Ribbon life (18 dots per character)

Figure 1-11. Ribbon Cassette Dimensions

7,000,000 characters

TM-U950/U950P Technical Manual

Dimensions, Weight, Finish

Dimensions

251 x 298 x 194.5 mm (9.88 x 11.73 x 7.66”) (W x D x H)

Weight

Approx. 5.6 kg (12.3 lbs)

Color

EPSON Standard Gray

Environmental Specifications

Temperature

No damage when dropped while printer is off.

Noise

63 dB (operating, measured in ANSI bystander position; printing on receipt and journal paper roll)

Reliability

Mechanics

MICR reader mechanism (only when the printer is used with the MICR reader):

TM-U950/U950P Technical Manual

Hardware Configuration

Main Unit Configuration

Printer mechanism

Figure 1-12. TM-U950 Printer Mechanism Main Unit Configuration

Electrical circuit and unit on cases

Figure 1-13. TM-U950 Electrical Circuit and Unit on Cases Main Unit Configuration

Main Unit Specifications

Paper feed motors

Receipt and journal paper feeding is performed by dedicated feed motors. Slip paper feeding is performed by using the journal paper feed motor and a journal/slip switching solenoid.

Motor type

4-phase, 48-pole PM type stepping motor

Drive voltage

24 V DC + 10% (including voltage drop caused by drive transistor)

Winding resistance

Drive frequency

500 pps (minimum pulse interval 2.00 ms)

Drive principle

Constant voltage drive, 2-2 phase induction

Carriage motor

Motor type

4-phase, 48-pole PM type stepping motor

TM-U950/U950P Technical Manual

Drive voltage

24 V DC ± 10% (including voltage drop caused by drive transistor)

Winding resistance

9 Ω ± 7% at 25°C (77°F), per phase

Current consumption (per motor)

Drive principle

Constant-current chopper drive, 2-2 phase induction

Carriage feed pitch

0.3386 mm (1/75”) per pulse

Print head unit (print solenoids)

Near-end sensors (journal, receipt)

A sensor is provided for the receipt and journal paper roll respectively. The sensors check the diameter of each roll and activate the near-end alarm when the diameter falls below a userdetermined value.

Paper roll sensors (journal, receipt) (*)

A sensor is provided in the paper path (receipt and journal side, respectively) of the printer mechanism. These sensors check for the presence of paper, and accordingly control loading of the paper roll.

(*)If the paper roll sensor detects the “no paper” condition while the cover is open, semiautomatic loading can be performed by inserting the paper roll into the paper path.

Slip paper insert sensor

This sensor is located in the slip paper loading path to detect the insertion of slip paper.

Slip paper eject sensor

This sensor is located in the slip paper eject path to detect ejection of slip paper. If ejection is not detected, the printer does not proceed to the next step.

Cover open sensor (*)

This sensor detects the condition of the printer cover. If the cover is open, the printer automatically goes off-line after the current printing operation and the carriage returns to the home position at slow speed. The printer goes back on-line when the cover is closed.

(*)If the paper roll sensor detects the “no paper” condition while the cover is open, semiautomatic loading can be performed by inserting the paper roll into the paper path.

Auto-cutter sensor

Home position sensor

This sensor detects the carriage initial position (on the receipt paper side) and the carriage abnormal operation.

Carriage sensor

This sensor outputs signal synchronized with the carriage operation, and detects whether the carriage operation is abnormal.

TM-U950/U950P Technical Manual

MICR Reader (when the printer is used with the MICR reader) (Not available for the TM-U950P)

Total number of checks

Check paper used for test is EPSON standard check paper. Checks must be flat, without curls, folds, or wrinkles.

Connectors

All connectors are located on the rear panel of the printer. (Refer to Figure 1-1.)

Connector panels

Figure 1-14. Rear Panel Connectors

Interface

See the Interface section in this chapter.

Power supply connector

This connector is for the AC adapter.

Note:

Be sure to ground the printer via the frame ground terminal on the metal strip on the rear panel.

Rev. A Features and General Specifications 1-17

Drawer kick-out connector (modular connector)

Pulse specified by ESC p command is output to this connector. The host can confirm the status of the input signal by using the DLE EOT, ESC u, GR r, or GS a (ASB) commands.

Connector type:

(*1) Drawer kick-out drive signal

The signal specified by the ESC p command is output from pins 2 and 5 of the connector.

n1 x 10ms n2 x 10ms

Figure 1-15. Drawer Kick-out Drive Signal Timing

(*2) Drawer open/close signal

The host computer can check the drawer open/close status with the DLE EOT, ESC u, GR r, or GS a (ASB) commands.

Input signal level (connector pin 3)

Low = 0 to 0.8 V

High = 2 to 5 V

TM-U950/U950P Technical Manual

Notes

Use a shielded cable for the drawer connection.

It is not possible to drive two drawers at the same time.

Use a solenoid rated for at least 24 Ω as the drawer kick-out solenoid. Otherwise, excessive current may damage the solenoid.

The drawer must be powered from the printer (connector pin 4).

Do not drive the drawer continuously.

Customer display connector (not supported on the TM-U950P)

This connector is for Epson customer display (DM-D series). Do not connect other customer displays.

Interface

Serial interface

MARK: -3 to -15 V (logical “1”/OFF) SPACE: +3 to +15 V (logical “0”/ON)

(Voltage measured at connector, referenced to SG)

(*)Can be set with DIP switches on the bottom of the unit (See Tables 1-9 and 1-10.)

On-line/off-line switching

This printer has no on-line/off-line switch. It automatically goes off-line in the following cases:

During self-test.

When the cover is open.

When the paper feed button (receipt or journal/slip) is used to advance the paper.

When printing has stopped due to no paper (“no paper” condition selected with ESC c 4).

During the interval between power-on (including reset using the interface) and the end of the initialization sequence, until data can be received.

When an error has occurred

During the macro execution switch waiting status.

Table 1-7. Interface Connector Specifications and Functions

TM-U950/U950P Technical Manual

Table 1-7. Interface Connector Specifications and Functions

Table 1-7a. Pin 20 Information

(*1) The “buffer full” condition in this case starts when remaining buffer space falls to 16 bytes or less and ends when it becomes 26 bytes or more. The printer ignores the data when the remaining space in the receive buffer is 0 bytes.

Note

Pins 8 — 19 and 21 — 24 are not used.

XON/XOFF control

When XON/XOFF control is selected, the XON and XOFF output timing is as described below. (XON code: 11H; XOFF code: 13H) Transmit timing differs depending on the DIP switch 5 of the bank 2.

Table 1.8. XON/XOFF Transmit Timing

(*1) XON is not transmitted when the receive buffer is full. (*2) XOFF is not transmitted when the receive buffer is full.

Notes on setting DIP switch 2-5 on

The printer stops printing mechanism operation but does not go off-line when an error has occurred, printing stops due to a paper-end, or paper is fed using the paper feed button.

When setting DIP SW 2-5 on to enable handshaking with the host computer, be sure to check the printer status by the GS a command and automatic status transmission function. In this setting, the default values of n for GS a is 2, and the printer automatically transmits the changes in on-line/off- line.

When using DLE EOT, DLE ENQ, and GS ENQ, be sure that the receive buffer does not become full. a) When using a host that cannot transmit data when the printer is busy:

If an error has occurred, DLE EOT, DLE ENQ, and GS ENQ cannot be used when the printer is busy due to receive buffer-full.

b) When using a host that can transmit data when the printer is busy:

When the receive buffer becomes full while transmitting data, DLE EOT, DLE ENQ, or GS ENQ using between the bit image data is processed as bit image data. The data transmitted when the receive buffer is full may be lost.

TM-U950/U950P Technical Manual

The following illustrates an example serial interface connection:

When connected to a DCE-type device, data should not be sent non-stop (without handshake).

DTE = Data Terminal Equipment

DCE = Data Circuit Terminating Equipment

Figure 1-16. Serial Interface Connection Example

Parallel interface

(Bidirectional parallel interface in accordance with the IEEE 1284 nibble/byte modes).

Copyright © 1994 by the Institute of Electrical and Electronic Engineers, Inc.

Compatibility mode

(Data transmission from host to printer: Centronics compatible)

Reverse mode

(Data Transmission from printer to host)

The STATUS data transmission from the printer to the host is accomplished in the Nibble or Byte mode.

This mode allows data transmission from the asynchronous printer under the control of the host. Data transmission in the Nibble mode are made via the existing control lines in units of four bits (Nibble). In the Byte mode, data transmission is accomplished by making the 8-bits data lines bidirectional.

Neither mode can operate at the same time as the compatibility mode, so switching is always required.

The 1284 Nibble/Byte modes may be subject to change without notice.

TM-U950P printer status and signals

NC: Not connected, ND: Not defined

Notes:

A prefix «n» to signal names refers to low active signals.

If the host does not have any one of the signal lines listed above, two-way communication fails.

For interfacing, signal lines should use twisted pair cables with the return sides connected to the signal ground level.

TM-U950/U950P Technical Manual

Interfacing conditions should be all based on the TTL level. In addition, both the rise time and fall time of each signal must be 0.5 µs or less.

Data transmission should not ignore the signal nAck or Busy. An attempt to transmit data with either signal, nAck or Busy, ignored can cause lost data. (Data transmission to the printer should be made after verifying the nAck signal or while the Busy signal is low.)

Interface cables should be as short as possible.

Precautions on receiving status from the printer

The printer status transmission is available by using the both-way communication facility in the Nibble/Byte mode in accordance with the IEEE 1284 mode.

The following precautions must be taken for receiving the status from the printer.

The allowable capacity of the printer’s internal buffer is 100 bytes. Status signals exceeding this capacity will be discarded. To prevent possible loss of status data, the host should always be ready for data reception (reverse mode).

When ASB is used, the host should be in the wait state for data reception (reverse idle mode). When this state is not available, the host should enter the reverse mode to always monitor the presence of data.

When ASB is used, preference should be given to the ASB status for transmission over the other status signals. Any accumulated ASB status signals left for transmission from the last to the newest ASB status transmission should be transmitted together at one time as one ASB status showing the change has been made, followed by the latest ASB status.

Example: In the normal (wait) state, the ASB status is configured as follows:

When the following sequence of operations is performed, near end detection, cover open, cover closed, the following pieces of data are accumulated.

When the ASB status is received following this, a total of 8 bytes of ASB will be transmitted as follows.

Switching between on-line and off-line

The TM-U950P printer does not have an on-line/off-line button. The printer goes off-line in the following conditions:

Between the time when the power is turned on (including reset using the interface) and when the printer is ready to receive data.

During the self-test.

When the cover is open.

During paper feeding using the paper feed button.

When the printer stops printing due to a paper-end (when the paper-end sensor detects a paper end or when the paper near-end sensor is enabled by ESC c 4 and detects a paperend).

During the macro execution standby state. (The macro is executed by pressing the paper feed button.)

When an error has occurred.

Notes on setting DIP switch 2-5 to ON

The printer mechanism stops but does not become busy when an error has occurred, the cover is open, printing stops due to a paper end, or paper is fed using the PAPER FEED button.

When setting DIP switch 2-5 to ON to enable handshaking with the printer, be sure to check the printer status using the GS a command and the ASB function. In this setting, the default value of n for GS a is 2. The printer automatically transmits the printer status, depending on on-line/ off-line changes.

When using DLE EOT, DLE ENQ and GS ENQ, be sure that the receive buffer does not become full.

When using a host that cannot transmit data when the printer is busy and if an error occurs, DLE EOT, DLE ENQ and GS ENQ cannot be used when the printer is busy due to a receive buffer-full state.

When using a host that can transmit data when the printer is busy and the receive buffer becomes full while transmitting bit-image data, a DLE EOT, DLE ENQ or GS ENQ used while sending bit-image data is processed as bit-image data, not as acommand. Secondly, any data transmitted when the receive buffer is full may be lost. Thirdly, data sent during data entry or data sent when the printer is busy may be lost regardless of the DIP switch setting.

Example: Check the printer status using ESC v or ESC u after transmitting each line of data and use the 2K byte receive buffer. Transmit one line of data so that the receive buffer does not become full.

TM-U950/U950P Technical Manual

Switches and Buttons

The power switch is located on the front side of the printer, at the lower left. The operation panel buttons are located on the right top side of the printer. Two banks of DIP switches are located on the bottom of the printer. (See Figure 1-1.)

Power switch

Turns the printer on or off.

Power switch cover guards the power switch from incorrect operation.

For using the cover see Mounting the Power Switch Cover in Chapter 3.

Operation panel buttons

The ESC c 5 command determines whether or not the operation panel buttons are active.

JOURNAL/SLIP FEED button

Notes

When the printer cover is open, these buttons are active regardless of the ESC c 5 setting.

Be careful not to catch your finger in the printer when you push these buttons with the printer cover open.

DIP switch settings for the TM-U950

Table 1-9. DIP Switch Bank 1

(*)Effective when a direct connection customer display is connected to the DM-D connector of the printer.

Table 1-10. DIP Switch Bank 2

When the interface connector pin 6 is used to reset the printer, the printer is reset at MARK with the RS-232C level.

When the interface connector pin 25 is used to reset the printer, the printer is reset at SPACE with the RS-232C level, and is reset at high with the TTL level.

Notes

DIP switches (excluding switches 1, 7, and 8 of switch bank 2) are effective only while the printer power is turned on. If the DIP switch setting is changed after the printer power is turned on, the change is not effective.

If DIP switch 7 or 8 of the switch bank 2 is on while the printer power is turned on, the printer may be reset, depending on the signal state. DIP switches should not be operated while the printer power is turned on

TM-U950/U950P Technical Manual

DIP switch settings for the TM-U950P

Table 1-9a. DIP Switch Bank 1

Table 1-10a. DIP Switch Bank 2

Note

DIP switches are effective only while the printer power is turned on. If the DIP switch setting is changed after the printer power is turned on, the change is not effective.

Indicators

The indicators are located on the operation panel. (See Figure 1-1.)

POWER LED (green)

TM-U950/U950P Technical Manual

Functions

Error Processing

Error detection

When the printer detects an error, it carries out the following operation sequence:

All running operations are stopped.

The printer goes off-line

The ERROR LED flashes. (See Error Types and Countermeasures on page 4-23.)

Error recovery

The commands DLE ENQ 1 and DLE ENQ 2 are used to recover from a recoverable error (*1).

Notes

If slip paper is selected and DLE ENQ 1 is used to recover from a recoverable error, the printer ejects the remaining slip paper and repeats the loading process.

When recovering from a slip paper eject error, the printer ejects the paper but does not repeat loading.

When the printer recovers from an error using DLE ENQ 2 while slip paper is selected, the printer first ejects the slip, then goes to 2-sheet mode.

When an unrecoverable error (*2) has occurred, turn off the printer as soon as possible. (*1) Errors (6) to (10) in Table 4-5 in Chapter 4 are the recoverable errors.

(*2) Errors (1) to (5) in Table 4-5 in Chapter 4 are the unrecoverable errors.

Data receive error

When an error is detected in data received by the printer (parity, framing, or overrun error), the data is either ignored or replaced to “?”, depending on the DIP switch setting.

Self-test

The self-test checks the following items:

Control circuit operation

Printer mechanism operation

Print quality

Control ROM version (on status printout)

DIP switch settings (on status printout)

MICR reader circuit function check (for printers with an MICR reader) For details about the self-test, please see Self-test in Chapter 4.

Hexadecimal Dumping

Hexadecimal dumping function

This function prints the data transmitted from the host computer in hexadecimal numbers and in its corresponding characters.

Starting hexadecimal dumping

Open the cover and turn the power on while pressing the RECEIPT FEED button, then close the cover. The printer first prints “Hexadecimal Dump” on the paper roll and prints the received print data in hexadecimal numbers and in its corresponding characters.

Notes

If no characters correspond to the data received, the printer prints “.”.

During hexadecimal dumping, any commands other than DLE EOT, DLE ENQ, and GS ENQ do not function.

Ending hexadecimal dumping

Hexadecimal dumping ends by turning the power off or resetting the printer after printing has finished.

TM-U950/U950P Technical Manual

Printing example.

Printing Operation

Sensors and printing operation

The ESC c 4 command can be used to select whether the printer should stop or continue printing when the “no paper” condition is detected. The following sensors are involved:

(*1) The journal and receipt paper roll sensors are used for auto-loading and cannot be used for paper-end detection. Printing may not be stopped even if the sensors are selected by ESC c 4. Therefore, use the near-end sensors to detect the paper roll end.

When “stop printing” is selected

Two-sheet mode

When the “no paper” condition is detected, the printer automatically goes off-line. To resume printing, close the cover after inserting a new paper roll.

Slip paper mode

When the “no paper” condition is detected, the printer continues to print on the printable area, ejects the paper, and waits for the paper to be removed. The printer then stands by for paper insertion.

Buffer full printing

After the maximum number of characters per line has been received and processed, the line is printed and the paper is advanced automatically when additional data is received.

Options

AC Adapter (PS-150)

Specifications

Input specifications

(If the adapter is not connected to a DC load of 2.0 A or less during power-on, the voltage will not build up sufficiently for operation.)

Journal Lock

Journal lock mechanism is a factory option. It protects journal paper roll from being taken away. For handling, see Journal lock key handling in Chapter 3.

TM-U950/U950P Technical Manual

Chapter 2

Mechanism Configuration and Operating Principles

Printer Mechanism Components

The TM-U950 impact dot matrix printer consists of the following eight components:

Printing assembly

Sensor assembly

Paper feed assembly

Slip paper assembly

Ribbon feed assembly

Stamp assembly (for printers with a stamp assembly)

Auto-cutter assembly

Paper roll-take-up assembly

These components are described in detail in the following sections.

Printer Mechanism Operating Principles

Printing Assembly

The printing assembly consists of the print head unit with nine vertical wires, and the parts shown in Figure 2-1.

Figure 2-1. Printing Asssembly

Print head unit movement

When the carriage motor is driven, the gear wheel turns in the direction indicated by the arrow , and the carriage feed pulley and carriage drive belt transmit the driving force so that the

head carriage fastened to the carriage drive belt moves in the direction of the arrow . When the carriage motor turns in the direction indicated by the arrow , the head carriage moves in the direction of the arrow .

Figure 2-2. Print Head Unit Movement

TM-U950/U950P Technical Manual

Printing operation

Wire movement for printing a single dot

1.When the drive pulse is sent through the drive coil, a magnetic field is induced in the core, and the lever plate is pulled in the direction a , the dot wire is pushed by the spring force of the wire towards the lever plate, which moves towards the platen assembly direction b .

2.The pushed-out dot wire contacts the platen via the ink ribbon and paper, so that one dot is printed.

3.The drive coil current is cut, causing the dot wire and lever plate to return to their original positions due to the spring action of the wire and the plate.

Figure 2-3. Dot Wire Operation

Forming a character

(9 x 9 dot matrix)

The carriage motor phase switching signal serves as a reference signal for powering the print solenoids in accordance with the carriage movement, to form a character. One rotation step of the carriage motor (7.5°) moves the print head unit by approximately 0.339 mm (0.013”).

For example, to form the character “2”, print solenoids 2 and 9 are first powered in sync with the carriage motor phase switching signal. Next, a half-dot timing delay TnH is introduced, and print solenoid 8 is powered. By continuing in this way, the character “2” is formed.

Figure 2-4. Print Timing Chart

Sensor Assemblies:

The sensor functions of the TM-U950 and TM-U950P are as follows:

(*) The near-end sensor is mounted on the case at the paper feed section

TM-U950/U950P Technical Manual

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Figure 2-5. Sensor Assembly

Home position sensor assembly

The home position sensor assembly is mounted on the left side of the stroke of the head carriage. The sensor detects the movement of the sensor plate in the rear section of the head carriage, to determine the position of the head carriage and any possible malfunction.

The home position sensor assembly consists of an LED and a photo IC. When the head carriage moves, the sensor plate passes between the LED and the photo IC, therefore blocking the light from the LED and causing a change in the output level of the photo IC. This change is used to generate the head carriage position signal.

Figure 2-6. Home Position Sensor Circuit Diagram

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