Bitbus to Ethernet?


Thread Starter

Lynn Linse

We have a customer who has a lot of legacy machine-tool equipment using
Bitbus - and traditionally used an PC card with a i8044 as the master.
They want to eliminate the i8044 card from the PC and perhaps access the
Bitbus network remotely from Ethernet.

Has anyone seen a vanilla "Bitbus-to-Ethernet" device which could
encapsulate the data under TCP or UDP?

Anyone else interested in such a product?

Best Regards;

Lynn August Linse, Senior Product Application Engineer
15353 Barranca Parkway, Lantronix Inc, Irvine CA 92618
[email protected]
Tel: (949)450-7272 Fax: (949)453-7132

Quin Systems are listed on the BEUG pages (at and their company web pages quote a "EtherBit2 Gateway Module allows a computer to control a BitBus network via TCP/IP over
Ethernet " (see

I have no experience of their products, however the subject is currently seared into my consciousness. I have a customer with old bitbus PC cards similar to your description, maybe
next year we will be looking for alternatives. Customer would want to keep bitbus on the plant and replace the cards.

Sue Platt
[email protected]
+44 1732 872 229 tel
+44 1732 872 231 fax
SPCS, 16-18 New Road, Ditton, Aylesford, Kent, ME20 6AD, UK
Replacing the 8044/8344 Bitbus processor will not be easy!

I spent a couple of years of my life doing bitbus with the 8044 and since several years doing Ethernet. I know them both quite well.

When intel did the 8044 they included some special automatic features in the hardware that supports bitbus very effectively. I know of no other hardware that will effectively drive bitbus without major problems. It is true that most of the funny additional hardware features were
directed toward the slave side of the bitbus, so it is possible, but not easy to drive the master side from something other than an 8044.

If you haven't looked it up, Bitbus is derived from the old IBM SDLC/HDLC standards (a BIT serial data stream, not a BYTE encoded in a fixed number of bits serial data stream like most uarts, etc) and you will have to have a microprocessor (or PC) with considerable code to translate the packets from Ethernet (or any other currently widely used network) to/from
Bitbus. You would have to start with hardware that included the SDLC/HDLC bit stream with flags, transparency bit insertions/deletions, crc calculations, etc and then add a hardware phase locked loop that creates the synchronous clock
needed to drive most SDLC/HDLC controllers from the actual bitbus data stream itself--no easy matter. And this is before you start creating the layers of software that drive this funny hardware....... overall, this is several man
years of work... we looked very hard at trying to use something other than the 8044 as a bitbus cpu and gave up: we used the 8044 as a peripheral to a 286 main cpu in one application, for instance.

Until you can replace the interfaces on the machine tools with something else (contact the manufacturers for sure!), you probably want to just put up with the bitbus stuff -- i fear you are stuck with it.....


----My opinion are mine only and no one else can have them-----
Steven B. Cliff
title: VP, Research & Development
Control Technology, Inc.
5734 Middlebrook Pike
PO Box 59003
Knoxville, TN 37950
We used 8044 based controller boards in our paper handling equipment, but as Intel stopped production on the 8044 microprocessor several years ago, we have been developing a new distributed control system based on (what else)

However, during my research in Bitbus chip availability and/or replacement solutions, I found nothing. Even the BITBUS users group ( website was only being updated on a 6th month or longer basis.

> Anyone else interested in such a product? <

I would be interested, if only as a way to support legacy equipment.

Pieter Hoeben

Both the 8044 and the 80C152 will be produced
again! Contact me if you need more info.
The 80C152 can be used for Bitbus too.

Pieter Hoeben

Hoeben Electronics Phone : +31 6 51590081
Ronkert 44 Fax : +31 13 5096025
5094 EW Lage Mierde Private : +31 13 5096024
The Netherlands E-mail : [email protected] <mailto:[email protected]>

Elmar Ottiger

Hello Lynn
Yes, there is a Bitbus - TCP/IP gateway. We developed a truly transparent gateway which can easily accessed by simply wrapping the old Bitbus messages into TCP/IP protocols via a simple API.

All bitbus features are supported. Additionally the gateway is hosted on a stand-alone, industry standard complient embedded PC platform.

For more information please contact "[email protected]", mailto:[email protected] or "":