A20B-3300-0600 Fanuc PCB Board A20B33000600 A2OB-33OO-O6OO

A20B-3300-0600 | FANUC Series 16i-B and 18i-B CPU Module — Pentium MMX / 16MB SDRAM / Plug-In Processor Card / F16iB F18iB

Series 16i-B and 18i-B — The i-B Machining and Turning CNC Platform

The FANUC Series 16i-B and 18i-B CNC controllers represent the B-generation hardware revision of FANUC's mid-high range i-series CNC. These systems power complex machining centres (16i-B) and turning centres (18i-B) where more axes, more advanced servo control, and more CNC options are required than the economy-tier 0i-B can support.

The A20B-3300-0600 is the Pentium MMX processor card for these controllers — the "brain" of the 16i-B/18i-B that executes all CNC control software from its 16MB SDRAM working memory.

Key Specifications

A20B-3300-060x — The Pentium MMX CPU Module Family

The 060x range is the Pentium MMX CPU module family for the i-B generation CNC platforms:

The 0600 is the 16i-B/18i-B specific variant — different from the 0602/0603 which serve the 21i-B. Despite all using the same Pentium MMX processor, the three boards serve different CNC main board sockets and are not interchangeable.

SDRAM — Synchronous Speed for CNC Workloads

The "CPU SDRAM 16MB" designation in the product description specifically identifies the memory technology as SDRAM. Standard DRAM uses an asynchronous interface — data transfer timing is independent of the processor clock, requiring wait states between memory accesses.

SDRAM eliminates these wait states by synchronising all memory operations to the system clock. When the CNC requests data from SDRAM, the first access requires a few clock cycles but subsequent accesses in the same row arrive at maximum bus bandwidth without additional wait states. For CNC software that accesses memory in sequential patterns — block-by-block programme execution, sequential I/O polling, PMC ladder scanning — SDRAM's burst mode delivers a consistent performance advantage.

Application Scenarios

16i-B CNC CPU module fault: A FANUC 16i-B machining centre develops CPU-level failures — CNC fails to initialise or generates CPU-related alarms. The A20B-3300-0600 is identified as the fault. Replacement restores the processor and its 16MB working memory.

18i-B turning centre processor upgrade: A Series 18i-B turning centre is upgraded from the standard Pentium module to the A20B-3300-0600 Pentium MMX module. Improved cache and SDRAM performance reduces block processing time for complex multi-axis turning programmes.

FAQ

Q1: What is the difference between A20B-3300-0311 (standard Pentium) and A20B-3300-0600 (Pentium MMX) for the 16i-B/18i-B?

A20B-3300-0311 uses the standard Intel Pentium processor. A20B-3300-0600 uses the Intel Pentium MMX — with doubled L1 cache, SDRAM memory (vs DRAM), improved branch prediction, and MMX instruction set. The Pentium MMX delivers better performance on cache-intensive workloads such as CNC look-ahead processing and PMC execution. Both serve Series 16i-B/18i-B.

Q2: Can A20B-3300-0600 substitute for A20B-3300-0602 (21i-B Pentium MMX module)?

No. Though both use the Pentium MMX with 16MB DRAM, A20B-3300-0600 is for 16i-B/18i-B and A20B-3300-0602 is for 21i-B. Platform-specific main board socket configurations and signal assignments make them non-interchangeable.

Q3: Does replacing A20B-3300-0600 affect CNC parameters or programmes?

No. CNC parameters and programmes reside in SRAM and FROM modules. Replacing the CPU card does not affect stored data. After fitting the replacement, the CNC boots from FROM and reads parameters from SRAM.

Q4: Does A20B-3300-0600 also contain the FROM and SRAM, or are those separate?

The A20B-3300-0600 contains the processor and 16MB SDRAM working memory. FROM (non-volatile system software storage) and SRAM (battery-backed parameters/programme storage) reside in separate memory modules that plug into positions on or near the main board — not integrated on the CPU card. This modular memory architecture is confirmed by CNC-Shopping for the 16i-B/18i-B platform.