I found an old piece of lab equipment in the dumpster.
Found along with it was a Compaq 386s that has a version of MSdos installed as well as the software for the instrument.
The lab equipment is very obscure, chemistry related, and from 1987. There are no manuals available.
The interface for the instrument is an unlabeled db25 female connector. I originally thought it was a parallel port connector, however when I took it apart and looked at the connected pins and their drivers, things did not match up.
The datasheets for the line drivers and receivers told me that they were specifically designed for rs423. This is a weird and kind of obscure standard.
For starters, wikipedia states that the standard has no actual standard pinout! Weird eh? I did find a pinout on a website, but it did not match mine.
From looking at various webpages, I determined that rs423 is single ended and considered backwards compatible with rs232. Basically it is like a single ended version of rs422, allowing 10 devices to be accessed on a bus. I also found a reference for a Sun Microsystems Server that listed the DB25 rs232 port as being RS232/RS423 compatible.
My decided course of action was to make an rs232 9 pin to rs232 25 pin adapter and pray for success. Tracing the various pins of the electronics I saw that the drivers and receivers seemed to agree at least somewhat with the pinout of an rs232 25 pin. I was using all my drivers and receivers and I wasn't connecting anything wrong.
Anyway, I wasn't in luck. Any suggestions on how to proceed?
Found along with it was a Compaq 386s that has a version of MSdos installed as well as the software for the instrument.
The lab equipment is very obscure, chemistry related, and from 1987. There are no manuals available.
The interface for the instrument is an unlabeled db25 female connector. I originally thought it was a parallel port connector, however when I took it apart and looked at the connected pins and their drivers, things did not match up.
The datasheets for the line drivers and receivers told me that they were specifically designed for rs423. This is a weird and kind of obscure standard.
For starters, wikipedia states that the standard has no actual standard pinout! Weird eh? I did find a pinout on a website, but it did not match mine.
From looking at various webpages, I determined that rs423 is single ended and considered backwards compatible with rs232. Basically it is like a single ended version of rs422, allowing 10 devices to be accessed on a bus. I also found a reference for a Sun Microsystems Server that listed the DB25 rs232 port as being RS232/RS423 compatible.
My decided course of action was to make an rs232 9 pin to rs232 25 pin adapter and pray for success. Tracing the various pins of the electronics I saw that the drivers and receivers seemed to agree at least somewhat with the pinout of an rs232 25 pin. I was using all my drivers and receivers and I wasn't connecting anything wrong.
Anyway, I wasn't in luck. Any suggestions on how to proceed?