Monarch 9835TM Power Conversion, Memory, Printer Control, Operator Control Panel, Communications

Functional Description 9820/9830/9835 Service Manual

Power Conversion

Power conversion interface receives AC and DC voltage from the Power Transformer assembly. 35VAC is converted to +12VDC and -12VDC, while the 40VDC input is converted to +25VDC and +5VDC.

Memory

Control Board Assebmly contains three types of memory: Flash, DRAM and SRAM.

Flash Memory

Flash memory contains the necessary BOOT code and Operating System functions for I/O routines used for communications, the application program, fonts, formats, and the Kernel/Library functions.

DRAM Memory

DRAM is used for variable storage, buffers, and image memory. The base memory configuration for the printer is 256K (16 bits).

SRAM Memory

SRAM (32K of non-volatile static RAM ) is used to store system parameters and machine totals. All relevant information is automatically stored in the SRAM when the printer is turned off.

Printer Control

Control Board Assembly controls all printer functions. It use a high performance, 32-bit, RISC based, integrated microcontroller. The microcontroller performs imaging and provides interfaces to printer control operations. Major functions of the board are:

Data Handling

During operation, communication with both the RS- 232 port and the High Speed parallel port is maintained. MPCL data received is transferred to Dynamic RAM (DRAM)

Printhead Thermal Control

Printhead thermal control operation is a dynamic closed loop servo circuit that adjusts the on/off duty cycle in response to a continuously monitored Printhead operating temperature and resistance.

Print Imaging

The Thermal Printhead Interface is controlled by the microcontroller. Page image data is transferred from Dynamic RAM to the thermal printhead as a serial data stream.

Motion Control

Motion control sub-system controls four DC motors. Two DC motors drive the Ribbon control, a stepper motor controls the platen drive, and a fourth motor drives the Peel Module.

Platen Drive Interface

Control Board Assembly controls the platen drive motor’s torque, speed and direction through the use of four phased 25Vdc output signals. Motor torque and direction is controlled by changing the sequence and pattern of the four signals. Motor speed is controlled by increasing or decreasing the speed of the digital pulse that make up the four phased signals.

Ribbon Drive Interface

Electronically controlled DC motors drive the ribbon over the printhead. The motors, and associated control software, control the tension of the ribbon web as the ribbon spools from the supply side to the take- up side. A speed-detection method using BEMF (Back Electromagnetic Motor Force) provides accurate ribbon tension control.

Analog to Digital Conversion

An ML2255 A/D converter, in conjunction with the microcontroller, monitors system functions. The A/D converter combines an 8-Bit A/D converter, 8-channel analog multiplexer, and a microcontroller-compatible, 8-bit parallel interface and control logic. The A/D converter monitors various system functions and provides information to the printers firmware to control the supply motion, print quality, etc.

Supply Detection & Tracking System

See Chapter 8, “Supply Sensing Systems” for more information.

Operator Control Panel

Printer Control Board uses a Peripheral Interface Unit (PIU) to control the operator control panel interface comprised of a three digit display, three push-button keys and three LEDs.

An optional 917 Keypad is available for the 9835 printer (offline batch entry).

Communications

RS-232 interface and the Centronics/IEEE 1284 compliant parallel interfaces are mounted on the Control Board Assy. Both are located on the left edge of the board and accessed by the user at the rear of the printer near the supply roll.

July 1998 TC9830SM Rev. B 7/98 Confidential 9