I. Model and Positioning

Model: JANCD-MB20C (Part Number is the same as MB20/B: DF8101356)

Series: JANCD → YASNAC J300 (Numerical Control) / JZNC-RK20 (Robot)

Version Evolution: MB20 (A) → MB20B → MB20C (Final Version)

Current Status: The original factory has discontinued production. The market mainly consists of disassembled / refurbished spare parts.

II. Core Improvements (Compared with MB20B)

Hardware Enhancement

Power Supply Circuit: 24V load capacity has been increased to 200mA, 10V to 30mA, with dual-channel redundant power supply.

Component Grades: Key components (rectifier bridge, capacitors, power modules) have been reduced to 2.5 times the original rating, with a temperature resistance of -40°C to +85°C.

Interference Resistance: The PCB has been re-designed, with multiple layers of ground and shielding added, significantly improving EMI/ESD performance.

Stability and Lifespan

Operating Temperature: 0 to 55°C (Version B: 0 to 50°C, Version A: 0 to 45°C).

Fault Probability: Alarm for ALM01 (Bus Error) and ALM02 (Low Battery) has been significantly reduced.

Lifespan: MTBF has been increased to 100,000 hours (Version B: approximately 60,000 hours). Compatibility

Fully compatible with all J300 daughter boards: PC20, MM20, JIF10, JSP02/04/11, etc.

Direct replacement of MB20(A)/MB20B, no rewiring required, no parameter reset needed.

III. Technical Specifications (Version C)

Power supply: DC24V ±10%, power consumption approximately 55W (slightly higher than Version B).

Backplane slots: 6 (CPU / Memory / Communication / Spindle ×2 / Reserved).

Interfaces: CN1 (24V), CN2 (5.5V battery), CN3 (MDI), CN4 (RS-232C), CN5 (I/O), CN6-CN8 (Expansion).

Battery: NEC 5.5V lithium battery (data backup, lifespan 3-5 years).

Size / Weight: Approximately 250×220×30mm, 2.6kg.

IV. Key Differences from MB20 (A)/B Table

Project MB20(A) MB20B MB20C

Temperature range 0–45℃ 0–50℃ 0–55℃

24V load-bearing 100mA 150mA 200mA

Interference resistance General Strong Extremely strong

ALM01 alarm Common Less Rare

Life (MTBF) 3–40,000 hours 60,000 hours 100,000 hours

Status Out of production Out of production Out of production (final version)

V. Adapter systems and typical configurations

Numerical control: YASNAC J300 lathe / machining center.

Robot: JZNC-RK20 arc welding / handling / painting control cabinet.

Standard configuration:

MB20C (motherboard) + PC20 (CPU) + MM20 (memory)

JIF10 (communication) + JSP04/JSP11 (spindle).

VI. Common alarms and handling

ALM01 (bus error): Version C rarely occurs; check that the daughter board is securely plugged in, the gold fingers are clean, and there is no oxidation on the back panel.

ALM02 (low battery): BAT light on → Replace with NEC 5.5V lithium battery.

ALM03 (CPU abnormal): Reinsert PC20, check if the 24V power supply is stable.

VII. Replacement suggestions

Prioritize Version C: Best stability and lifespan, suitable for equipment with 24-hour continuous operation.

Replacement sequence: Version C can replace Version B/A; Version B can replace Version A; Version A cannot replace Version B/C.

Spare parts status: Original factory has stopped production, market mainly offers OK after disassembly testing / refurbished with warranty.