ti-100 with blown triac output

Hi there,
(this comes from the 'way-back machine')

An old TI-100 has blown one of its Triac Outputs.

I'm attempting to relay to a colleague, over the phone,
how to delete the currently used Output Coil, and insert a replacement (unused) Output Coil.

apparently this is not as straight forward as i would have thought.
yes no maybe ??? his sketchy documentation leads him to 'error' prompts.

thanx in advance for any advice that i may pass on!
p

What is the Error Message?

Hi Terry,

apparently,
he wants to change Output 64 to Output 52.
using a TI-103 Programmer:

he finds the step,
keys in: [out] 64 [ent]
and the resulting display is "E"

[back step] and [step] show that nothing has changed.
Output 64 still exists.

quote from Keithkyll

-------------------------------------
The first problem I see is:
keys in: [out] 64 [ent]

should be:
keys in: [out] 52 [ent]

I guess "E" means "error". Is the PLC in Run Mode?

Try adding code instead of edit. I don't know the TI, so you'll need to translate:

Load 64
Out 52
-------------------------------------

yes Keith, you are correct - typo! that's me in my haste.
i'm sure he entered it as you noted.

he has of course tried the many forms of editing:
editing - deleting / inserting - inserting / deleting.
upside down and backwards!
in programming mode yes.
it almost seems like there is a protect switch,
or, that it's a read only memory, etc.

the unit is in fact a TI-164

well apparently it looks as if they had decided at one time to burn them onto a prom!
so no wonder it wouldn't accept a change!

thanx for the help.
p

Seems replacing the bad Triac may be the easiest way out.

Can you replace the PROM with a battery backed SRAM? Check the format of the PROM. A M48Z35 from ST is 32 x 8K. It should drop in.
EPROM burners will also read/write SRAMS. Read the PROM, then write it to the SRAM. Now you should have a mirror copy of the program in a chip that you can read/write.

I don't know the TI well enough to know if this will work. Just an idea if you can make it happen.

If they haven't got a replacement module... (does it use modules?) then if they can afford a bit of down-time... they must be down now... it really shouldn't be a tough thing at all for someone, with a steady hand, to replace the bad Triac... remove the old Triac and solder in the new Triac.

The chip-number should be apparent... TI does things that way.

Thanks Terry, thanks Keith,
your suggestions are most appreciated.

Up to now, they've been sending their failed modules out for repairs.
Now that I've (we've !?!) been involved, I think they'll look into some writeable memory types, and a more local source ( me! ) for board repair.

In fact, the most likely plan of attack is to upgrade to a modern PLC !

cheers!
paul

I think that I still have a few rack-fulls of old TI plug-ins...If you need some, send me a PM...
David