Debugging a FOURTH program 1992 era

**jlorda** · May7-09, 02:56 PM

I work at a Bio tech company in Ma. We manufacture a Feline Leukemia Virus vaccine. We currently use a TCS 6366 controller(1987 vintage) to control our pH in our 500 L fermenter. The 6366 controller has been giving us some erratic out puts. We would like to program another 6366 as a backup so we can service the failing controller. In order to program the controller we have to use a 486 PC running win 3.1 using an RS232 interface to the front of the controller.
We have not had any success programing a backup controller. The program that gets uploaded to the controller is written in programming language FOURTH. Those of us working on this problem believe that there is a problem with the FOURTH program or the parameter file that loads with it. We have loaded other programs on to the controller with success (agitation and temp control). I will be attaching the two fourth files with this post. If anyone has any suggestions on the program logic or parameter files your thoughts would be greatly appreciated.

**jlorda** · May7-09, 03:02 PM

Thank You in advance...

**CRGreathouse** · May7-09, 03:12 PM

That's rough. The files are mercifully short, but Fort is famous as a write-only language -- very hard to debug, especially when written in a terse style like you have here.

But I can't even start figuring out what it does, because it uses WORDs I'm not familiar with, not standard Forth: GT, GP, BN, ST, etc. Where are these defined? They're not in F1U6.TXT.

**jlorda** · May7-09, 03:26 PM

This is all we have to go on. We have been trying to get our hands on the documentation that came with this program. But that was probably gone long ago. F1U6.TXT is just the program. The dictionary file is F1U6parm this gives the variables for the program from what I can tell. This is all we have to go on. Thanks for the reply.

**jlorda** · May7-09, 03:43 PM

The program is supposed to keep the pH in the fermentor at pH 7.10 the set point(local set point). As the Bacteria grow the pH begins to drop below the set point the controller will open a valve to a pressure vessel that contains Sodium Hydroxide 5N for a given periop of time. There is also a subrutine for an acid addition but we never need to add the acid for this particular fermentation of recombinant ecoli.

**CRGreathouse** · May7-09, 05:44 PM

Originally Posted by jlorda

This is all we have to go on. We have been trying to get our hands on the documentation that came with this program. But that was probably gone long ago. F1U6.TXT is just the program. The dictionary file is F1U6parm this gives the variables for the program from what I can tell. This is all we have to go on. Thanks for the reply.

I didn't expect that there was documentation. What I meant was that I don't even think this program will run at all in its present state. It seems to need an external library or a third file. (Anyone with more Forth experience is welcome to post to the contrary!)