GE-FanucIC600BF949LSeries Six ASCII/BASIC Coprocessor Module, 28K User Memory, Dual Serial RS-232C / RS-422

Product Description

What this part is

GE Fanuc IC600BF949L, the 28K ASCII/BASIC Module for the Series Six programmable controller. Despite the short catalogue name, this is not a “basic” or entry-level board — BASIC here is the programming language. The module is a serial coprocessor with a full BASIC interpreter on board, plus two serial ports, that runs its own user-written program alongside the PLC ladder without consuming CPU scan time.

Decoding the order code

IC600 – GE Fanuc Series Six / Series Six Plus familyBF – supplied as circuit board and faceplate together (the YB prefix on this platform is the bare board, no faceplate)949 – the 28K byte user-memory version of the ASCII/BASIC module; IC600BF944 is the 12K byte version of the same boardTrailing letter L – hardware revision level, not a capacity or function change

Published specifications

Function: ASCII/BASIC coprocessor module with resident BASIC interpreterUser program memory: 28K bytes, battery-backed RAMSerial ports: two, independently configurable. Port 1 RS-232C; Port 2 RS-232C or RS-422Data rates: 110 to 19,200 bps, switch selectableData format: 7 or 8 data bits; even, odd or no parity; 1 or 2 stop bitsMaximum cable length: 50 ft (15 m) on RS-232C; 4,000 ft (1,200 m) on RS-422Isolation: 1,500 V rms transient, port to logic commonPower: 5 V DC from the rack supply, 20 units of load; no +12 V requiredInterrupts: 16 (software, timer and event driven)Real-time clock on board for time-stampingRack space: one I/O slot in a Series Six CPU rack or High Capacity I/O rackOperating temperature: 0 to 60 °C; humidity 5–95% non-condensing; altitude to 10,000 ft

What these specs mean in practice

This is the board you fit when ladder logic is the wrong tool. The BASIC interpreter gives you floating-point maths, trigonometric functions (SIN, COS, TAN, LOG, ABS, INT), and string handling (STR$, CHR$) that Series Six ladder cannot do cleanly. Typical duty is formatting reports to a printer, logging batch data, parsing serial strings from a bar-code reader or scale, translating a foreign serial protocol, or running recipe arithmetic.

The key architectural point is that it is a coprocessor, not an instruction extension: the module holds its own program in its own 28K of RAM, and ladder logic passes variables to it and reads results back through %I, %Q and %R references using special CPU commands. Scan time is not affected by how much work the BASIC program does. That makes it a practical retrofit for adding logging or protocol conversion to an existing machine without touching the control program’s timing.

Port choice matters for distance. RS-232C on Port 1 is limited to 50 ft, which covers a printer in the same panel or an adjacent cabinet. If the device is across the plant, use Port 2 in RS-422 and you have 4,000 ft and the option of a daisy chain. The 1,500 V rms port isolation is what keeps those links stable in a bay with arc welders or large drives on the same supply.

Firmware and program memory: read this before you buy:
User memory is battery-backed RAM. On a surplus board of this age assume the backup cell is exhausted and that no usable BASIC program is retained. Plan to fit a fresh battery and load your own program. If your application depends on recovering a program that was resident on this specific board, do not assume it survived.

What is included

Circuit board with faceplate, as pictured — that is what the BF prefix denotes. This listing does not include a rack, backplane or CPU rack power supply; a CPU, memory module or Communications Control Module; serial cables or mating D-type connector kits for either port; a printer, modem or terminal; a fresh backup battery; the ASCII/BASIC Module Manual (GEK-25398); or Logicmaster 6 programming software. Both serial cables are built to the connected device’s requirements and are not supplied.

Installation and setup notes

The module takes one I/O slot and must sit in a CPU rack or a High Capacity I/O rack — it is not supported in a standard low-capacity I/O rack. Set the DIP-switch addressing and the per-port baud rate, parity and duplex options before insertion; both ports configure independently. Use the extraction/insertion tool supplied with the CPU rather than pulling the board by hand. Faceplate LEDs show module OK plus per-port transmit and receive activity, which is the fastest way to prove a comms fault is cabling rather than the board. If the module sits at the end of an RS-422 run, check terminating-resistor configuration. Handle as static-sensitive.

Interchange guidance

All IC600BF949 revision letters (-A through -Z, including this L) are the same catalogue item. IC600BF944 is not an equivalent — same footprint and same function, but only 12K bytes of user memory, so a 28K program will not fit. Going the other way, a 12K program will run in this board. The bare-board variant without faceplate is listed under IC600YB944 for repair use; if you need the faceplate, the BF number is the one to buy. Related Series Six items sold separately include the IC600LX624 combined memory module, IC600CB516/CB536 Communications Control Modules, and IC600BF/IC600YB discrete and analog I/O boards. Also searched as IC600-BF-949L, IC600 BF 949, BF949, IC600BF949M, and GE Series 6 ASCII BASIC module.