1. General Description

JANCD-FC904 is an upgraded control panel interface board for YASNAC I80 CNC system. It establishes signal connection between main controller and machine operation panel, processing keys, selector switches, emergency stop, handwheel and indicator lights. Pin-to-pin compatible with FC903, featuring enhanced anti-interference performance for direct replacement.

2. Basic Specifications

Compatible System: YASNAC I80 / I80M

Mount Backplane: JANCD-FC001, 1 full slot

Board Dimension: 216 × 140 mm

External Interface: 50-pin flat cable connector

Internal Bus: System bus connecting to FC500

Working Voltage: DC 24V

Operating Current: 0.3A

Operating Temperature: 0°C ~ +60°C

Storage Temperature: -20°C ~ +70°C

Relative Humidity: ≤80% RH, non-condensing

3. Key Features

Full Panel Signal Processing

Receives signals from mode switch, cycle start, feed hold and emergency stop

Drives status LED indicators for power, alarm and axis operation

Built-in signal conditioning, ESD and surge protection

Upgrade Advantage vs FC903

Identical functions and mounting dimension

Fully interchangeable without wiring modification

Optimized circuit design for higher stability and noise resistance

System Matching

Works cooperatively with CPU board and PLC main board

Suitable for standard I80 machine configuration

4. Compatibility & Configuration

Required Matching Boards

CPU Board: JANCD-FC250 / FC251

PLC Core Board: JANCD-FC500

Installation Backplane: JANCD-FC001

Typical System Layout

Standard machining center: FC251 + FC500 + FC904 + Display board

Usage Restriction

Maximum 1 board installed per single CNC system

5. Common Fault Phenomena

Unresponsive buttons: Loose or damaged flat cable connector

Indicators off: Defective drive chip or abnormal power supply

Intermittent communication failure: Poor backplane contact

Handwheel malfunction: Signal channel damage or wrong wiring

6. Application Range

YASNAC I80 series lathes, milling machines and machining centers

Replacement service for ageing FC903 board

Retrofit and maintenance of Hitachi Seiki machine tools