GEIC600BF900ASeries Six Local I/O Transmitter Module — Coaxial Remote I/O Link, 153.6 kbit/s, 1500 V AC Isolation

Product Description

What this part is

This is a Series Six local I/O transmitter module — a communications card, not an I/O card. In a GE Fanuc Series Six or Model 600/6000 system it sits in the processor end of the link and transmits input and output data between the CPU rack and I/O racks placed away from the processor. It takes the parallel signals off the Series Six backplane, serialises them, and drives them down coaxial cable to the receiving end. Nothing on this module connects to a field device.

Correcting the source data

Earlier copy on this listing described the IC600BF900A as an output module. It is not, and the difference matters more than most catalogue errors. An output module switches field loads; this module moves I/O data between racks. If you order this expecting sixteen points of 115 VAC switching, nothing on the faceplate will do what you need. Series Six discrete output cards are the IC600BF9xx numbers immediately around it — BF904 (115 VAC 8-point output), BF910 (115 VAC isolated output), BF942 and BF943 (analog output) — which is exactly why the mix-up happens. The 900 in the number is the local I/O transmitter, and it is the reason this card is worth more than a plain output card: communications modules are far scarcer in the surplus channel than I/O.

The brand field on this record reads GE. Series Six is a GE Fanuc Automation product and is traded under both GE and GE Fanuc; both names are correct enough that we have left the field alone, and both are worth searching.

Decoding the order code

IC600 – GE Fanuc Series Six / Model 600 and 6000 product lineBF – the rack-mounted module block within Series Six900 – local I/O transmitterA – hardware revision letter. Series Six revision letters run A through Z on many part numbers and generally interchange; match the 900 first.
Also written IC600-BF-900-A, IC600 BF 900 A and IC600BF900. Related factory numbering seen in the market includes IC600BF900K and the IC600 BF900LCA1 configured form.

Published specifications

Function: local I/O transmitter — serial link between Series Six CPU rack and remote I/O racksPlatform: GE Fanuc Series Six, Model 600 and Model 6000Slot: any standard Series Six I/O rack slotBackplane interface: 48-pin edge connectorSerial interface: 25-pin D-subCable: 75-ohm coaxialData rate: up to 153.6 kbit/sIsolation: 1500 V AC between field cable and backplane logicStatus indication: two front-panel LEDs, power and data activityOperating temperature: 0 to 60 °CInternal PCBs: oneEnergy storage: none — no batteries, no supercapacitorsWeight: approximately 0.9 kg (1.9 lb) as shipped by dealers; the bare card is lighter

What these specs mean in practice

The point of a local I/O transmitter is distance. Instead of running dozens of field wires back to a central rack, you put the I/O rack out near the machine and run one coaxial cable back. On this generation of hardware that buys you a few hundred metres of separation at 153.6 kbit/s, which is slow by any modern standard but entirely adequate for the scan rates a Series Six system runs at. The tradeoff is determinism: every remote rack adds link latency to the I/O update, so time-critical interlocks belong in the CPU rack, not out on the end of the coax.

The 1500 V AC isolation between cable and logic is the specification that keeps a ground-potential difference between two buildings or two motor control centres from destroying the processor. On a plant where the remote rack sits on a different earth reference, that isolation is the whole reason this architecture is safe, and it is a reason not to improvise a substitute.

No batteries and no energy storage on the card means nothing to replace on a surplus unit and nothing that degrades on the shelf. Unlike a Series Six CPU or memory module, a transmitter card that was good when it came out of service is good now.

What is not included

Transmitter module only, one card. Not supplied: the 75-ohm coaxial cable, connectors or terminators; the mating receiver module at the remote rack end (a transmitter is half a link and useless alone — you need the corresponding receiver); the Series Six I/O rack or CPU rack; the rack power supply; and any terminal cover or documentation. If you are commissioning a new remote drop rather than replacing a failed card, budget for the receiver and the cable run as well.

Installation and setup notes

Snap the module firmly into a standard Series Six rack slot; power the rack down first. Use 75-ohm coaxial cable for the link and set the end-of-line termination switch correctly — an unterminated or double-terminated coax run is the classic cause of intermittent remote-rack dropouts that look like a failed module. The two faceplate LEDs give you power and data activity, so a lit power LED with a dark activity LED points at the cable or the far end rather than at this card. The link watchdog resets communication after roughly 100 ms of inactivity, which means a marginal cable shows up as periodic rack faults rather than a clean failure.

Interchange guidance

Search forms include IC600BF900A, IC600BF900, IC600-BF-900-A, IC600 BF 900 A, IC600BF900K and IC600 BF900LCA1. Within the 900 designation, revision letters are the interchangeable dimension. IC600BF904, BF910, BF942 and BF943 are different modules in the same rack family — output and analog cards, not equivalents to a transmitter, and not substitutes. Series Six is long discontinued with no factory replacement; surplus, reman and board-level repair are the supply channels, and communications modules are the scarce end of that market.