Manual | Digi Sm320 Service

DIGI SM-320 is a dual-function digital scale designed for retail and production, combining electronic cash register (ECR) capabilities with high-speed label printing Core Functionality Dual Operation

: Acts as both a price-computing scale and a point-of-sale terminal with receipt or label printing High-Speed Printer

: Features a built-in thermal head printer with a maximum speed of 105 mm/sec and a lifespan of approximately 100km Capacity Options : Available in multiple weighing ranges: Advanced Memory : Standard 2MB non-volatile memory stores up to 8,300 items (PLUs) digi sm320 service manual

, with optional upgrades to 4MB or 8MB for up to 38,000 items Hardware & Interface

: Dual-line backlit FSTN LCD (202 x 32 pixels); specifically displays tare (4 digits), weight (5 digits), unit price (6 digits), and total price (7 digits) Keyboard Layouts SM-320B (Bench) : 32 preset keys SM-320P (Pole) : 56 preset keys on a raised display rack SM-320BS (Self-Service) : 120 large quick-selection keys Connectivity : Integrated , and a RJ-11 cash drawer port; optional (802.11a/b/g/n) is available Service & Maintenance Features SM-320 | Retail - DIGI (TERAOKA) DIGI SM-320 is a dual-function digital scale designed

2. Key Technical Specifications

The service manual typically dedicates a section to the hardware specifications. Understanding these is crucial for component replacement and compatibility checks.

• Capacity and Resolution: The SM320 generally comes in various capacity models (e.g., 6kg, 15kg, 30kg) with corresponding resolutions (e.g., 1g, 2g, 5g). The manual details the specific calibration parameters for each model.
• Display: It features a dual display system (operator and customer side), often utilizing Fluorescent or LCD technology.
• Printer Mechanism: The SM320 utilizes a thermal line printer. The manual specifies the print speed, dot density, and supported paper width (usually 58mm or 60mm thermal paper).
• Interface: Technical pinouts for serial ports (RS-232C) are provided for connecting to PCs or networks.

2. Common Failure Modes & Fixes

| Symptom | Likely Cause | Fix | |---------|--------------|-----| | No power LED | Fuse F1 (internal, 3A slow-blow) blown | Replace fuse; check for short on VBAT input | | TX LED blinks but no link | Antenna mismatch or coax damage | Test with dummy load; measure SWR (<2:1) | | Intermittent serial data | Loose terminal block screws | Re-torque; check for cold solder joints on DB9 | | Overheating | Failed thermal pad between PA and chassis | Replace thermal pad (1.5mm, 3W/mK) | | Firmware corrupt | Power loss during update | Use XMODEM recovery via bootloader (hold ‘DEF’ button at power-up) | Capacity and Resolution: The SM320 generally comes in

Chapter 7: Common Replacement Parts

• Cellular module: If removable – Sierra Wireless MC8775 or Digi 1000-000072.
• Capacitors (bulk): 470µF/35V (low ESR), 100µF/10V (tantalum – replace with polymer if bulging).
• Fuse: LittelFuse 1812L110 (resettable).
• Battery (RTC backup): CR1225 (soldered tabs).

Critique / Caution

• Check your Serial Number: Digi often revises hardware without changing the model number. Ensure the manual revision matches your unit's serial number range, or the wiring diagrams might be slightly off.
• Copyright: Be wary of websites selling "unauthorized" copies for $5; they are often low-resolution scans that are unreadable for the schematic sections. It is usually better to source this through an authorized Digi dealer.

Adjusting Print Darkness

In service mode, look for PRINT DARKNESS or ENERGY setting. Typical range: 80-120. Higher values increase contrast but reduce head life.