1. General

• Part Number: JANCD‑SP20C（often SP20C‑02）

• Manufacturer: Yaskawa Electric / Motoman Robotics

• Function: CRT/MDI keyboard controller + Ethernet/RS‑232 communication

• Applicable Systems:

  • Motoman ERC robot controller（late builds）

  • YASNAC LX3 / MX3 CNC（with MDT‑948B‑3 CRT）

• Status: Discontinued（used/refurbished only）

• Origin: Japan

• Weight: ~0.32 kg（0.7 lbs）

2. Specifications

• Power: 24 V DC（backplane）

• Current: Up to 2 A

• Operating Temp: 0 °C to 55 °C

• Storage Temp: −20 °C to 60 °C

• Humidity: ≤95% RH（non‑condensing）

• Comms: Ethernet + RS‑232（key upgrade over SP20B）

• Keypad I/F: 20‑pin flat cable to JANCD‑SP19

• Video: Monochrome CRT out（MDT‑948B‑3）

3. Main Functions

• Keyboard scanning: SP19 key matrix read, debounce, encode

• CRT control: Text/status display for operator panel

• Front‑panel I/O: Mode switches, LEDs, operator controls

• Dual‑port comms:

  • Ethernet: Network data exchange, diagnostics

  • RS‑232: Serial link to peripherals/host

• System bridge: Data transfer between HMI and main CPU

4. SP20C vs SP20B（Key Differences）

• SP20B: +12 V, ~0.5 A, no Ethernet（only RS‑232）

• SP20C: +24 V, up to 2 A, Ethernet + RS‑232；late‑model ERC/LX3/MX3

5. Compatibility

• ✅ Motoman ERC（late revisions）

• ✅ YASNAC LX3 / MX3（all, with MDT‑948B‑3）

• ❌ XRC, NX100, DX100, DX200, etc.

6. Common Issues

• Keypad dead: Check SP19 cable, membrane, fuse

• No CRT: Verify 24 V, CRT cable, video driver

• Comms fail: Ethernet link/IP settings; RS‑232 wiring/baud

• Board not recognized: Clean gold fingers, re‑seat

7. Installation

• Power off, wait 5 min discharge

• ESD protection（wrist strap）

• Insert into dedicated backplane slot

• Connect SP19 flat cable + CRT cable

• Configure Ethernet/RS‑232 parameters

• Power on, test keypad, display, comms