A02B-0307-B502 FANUC 31i-A CNC Control Basic Unit 2-Slot

A02B-0307-B502 FANUC Series 31i-A CNC Control Basic Unit

Technical Specifications

• Brand: FANUC
• Model: A02B-0307-B502
• Series: FANUC Series 31i-A
• Category: CNC control basic unit (2 slots)
• Supply voltage: 24 VDC ±10%
• Heat output: 33 W (7.2" STN monochrome LCD-mounted type)
• Operating ambient temperature: 0 to 58 °C
• Storage/transport temperature: −20 to 60 °C
• Relative humidity: 75%RH or less normal; up to 95%RH for short periods (≤1 month), no condensation
• Weight: approximately 2.2 kg
• Dimensions: outline drawing per FANUC B-63943EN/02 Appendix A
• Protocols: RS-232C, I/O Link, Ethernet

Communication and Expansion

• The control unit provides three built-in ports: JD36A (RS-232C), JD51A (I/O Link), and CD38A (Ethernet).
• These ports support RS-232C, I/O Link, and Ethernet protocols for machine integration.
• Two backplane slots accept additional I/O modules for expanded communication.
• FANUC documents these ports in B-63943EN/02 §3.2.1, Table 3.4.2(a), Appendix A Fig.U1, p.174.
• The official BOM listing appears in B-63945EN/02 Maintenance Manual, p.200.

Electrical and Environmental Ratings

• The unit runs on 24 VDC ±10% supply voltage.
• Heat output reaches 33 W for the 7.2" STN monochrome LCD-mounted type.
• Operating ambient temperature ranges from 0 to 58 °C.
• Storage and transport temperature ranges from −20 to 60 °C.
• Relative humidity stays at 75%RH or less under normal conditions.
• Short periods (≤1 month) tolerate up to 95%RH without condensation.
• FANUC lists these values in B-63945EN/02 §5.10, p.329/printed 356.

Physical Characteristics

• The LCD-mounted basic unit weighs approximately 2.2 kg.
• FANUC publishes the outline drawing in B-63943EN/02 Appendix A and Fig.U1.
• The two-slot design accepts extra I/O modules inside the control cabinet.
• This hardware identity matches aftermarket listings and the B-63943EN manual.

Lifecycle Status

• The A02B-0307-B502 belongs to the legacy 30i-A/31i-A/32i-A generation.
• FANUC superseded this generation with the Series 30i/31i/32i-B.
• We last verified this lifecycle status in 2026-09.
• Current stocks serve maintenance and retrofit needs for existing machines.

Installation Guide

• Confirm the cabinet supplies 24 VDC ±10% before you connect the unit.
• Mount the control unit so airflow keeps ambient temperature within 0 to 58 °C.
• Keep relative humidity at 75%RH or less and avoid condensation on the board.
• Connect JD36A (RS-232C), JD51A (I/O Link), and CD38A (Ethernet) to matching devices.
• Install backplane I/O modules in the two slots when your application needs expansion.
• Follow FANUC B-63945EN/02 and B-63943EN/02 wiring and outline drawings.
• Check all connections before you apply power to the control.

Packing List

• 1 × FANUC A02B-0307-B502 Series 31i-A CNC control basic unit
• 1 × protective anti-static bag
• 1 × shock-absorbing foam packaging set
• 1 × outer shipping carton

Shipping and Support

• We ship orders within 5 days after payment confirmation.
• We use FedEx, UPS, and DHL for international delivery.
• We support returns within 30 days of delivery.
• All units ship as brand-new original stock, subject to availability.

FAQ

• Q: What supply voltage does the A02B-0307-B502 require?
  A: The unit requires 24 VDC ±10%, as FANUC specifies in the connection manual.
• Q: How many expansion slots does this control unit have?
  A: It provides two slots for backplane I/O modules.
• Q: Which communication ports does this control unit include?
  A: It includes JD36A (RS-232C), JD51A (I/O Link), and CD38A (Ethernet).
• Q: What is the operating temperature range?
  A: The control unit operates from 0 to 58 °C ambient temperature.
• Q: How much heat does the unit produce?
  A: The 7.2" STN monochrome LCD-mounted type produces 33 W of heat.
• Q: How much does the unit weigh?
  A: The LCD-mounted basic unit weighs approximately 2.2 kg.
• Q: Is this model still in production?
  A: No, it is a legacy unit superseded by the Series 30i/31i/32i-B.
• Q: Do you have stock and how fast do you ship?
  A: We keep this item in stock and ship within 5 days via DHL, FedEx, or UPS.
• Q: What is your return policy?
  A: We accept returns within 30 days and supply brand-new original units.