Corcomp PDM99 peripherial diagnostic module

[johnph3]

HELP !! Any body out there have an original CorComp PDM99 with the loop back plug that came with it? The Manual does not describe how to build one and I would like to have one. Please send me directions

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Edited April 21, 2022 by johnph3

[johnph3]

OK still no help on making a loop back plug for ti RS232 in PEB. I have a Corcomp pdm99 test cartridge which has the loop back test in it but alas I have no loop back plug. I have failed after trying several times following suggestions. Pin 2 to 3 by itself _nogo, pins 2 to 3 and 8 to 20 nogo pins 2 to 3 and  pins 20 to 6 and 8 no go.  Seems like there should be a simple pin jumpers to make a loop back plug without using led's, resistor's and all that fancy stuff. I know Corcomp issued a loop back plug with their PDM-99 module how ever when I bought mine (Ebay) it didn't come with it and the manual does not show pin out for it. If you have the pin out for a loop back plug simple RS232 test, please post it so I can finish this. Or if you have a PDM original loop back plug to sell I would be interested, (if it was not an arm and a leg so to speak).

[Stuart]

2 hours ago, johnph3 said:

OK still no help on making a loop back plug for ti RS232 in PEB. I have a Corcomp pdm99 test cartridge which has the loop back test in it but alas I have no loop back plug. I have failed after trying several times following suggestions. Pin 2 to 3 by itself _nogo, pins 2 to 3 and 8 to 20 nogo pins 2 to 3 and  pins 20 to 6 and 8 no go.  Seems like there should be a simple pin jumpers to make a loop back plug without using led's, resistor's and all that fancy stuff. I know Corcomp issued a loop back plug with their PDM-99 module how ever when I bought mine (Ebay) it didn't come with it and the manual does not show pin out for it. If you have the pin out for a loop back plug simple RS232 test, please post it so I can finish this. Or if you have a PDM original loop back plug to sell I would be interested, (if it was not an arm and a leg so to speak).

Reading a review of the PDM99 cartridge, it looks like the loop back test actually sends data between the two RS-232 ports, rather than looping through just one port. So you need to wire a plug to connect the two ports together. The RS232 card user manual has the pinout for the two ports on the DB25 connector.

 

(Just found the PDM99 manual that you uploaded in another thread. That says the same thing, and there's a handwritten note on one of the pages that says connect pins 3 and 14 - which is data out from RS232/1 to data in to RS232/2.)

Edited April 26, 2022 by Stuart

[johnph3]

Yes that is hand written in my manual. I did try this first and it did not work. Wonder if some other pins along with these need connecting? What I'm trying to say is 3 to 14 by itself doesn't work. Thanks

Edited April 26, 2022 by johnph3
left part out

[Stuart]

Have a go with 3-14, 2-16, 8-19, 12-20.

[ti99iuc]

Sorry I have completely forgot about this:

 

 

Hope this can help.

 

 

[+dhe]

I believe 2-3 should work. Are using this to test  a corcomp rs232? 

Sometimes PDM99 is not so happy with myarc hardware.

[johnph3]

Yep that works fine on the regular diagnostic disk I have. I forget where I got it but it doesn't work on corcomp's diagnostic.

I think it its because corcomp is testing loop from rs232 1 to rs232 2. Output 1 to input of 2.  the connections you have in the photo according to the schematic I have show output 0 (which is 1) to input 1 ( which is 2) 3 to14 and output 1 (which is 2) to input 0 (which is 1) pin 16 to 2. But cor comp test program must be looking for something else in jumpers.  Thanks by the way for sharing the information you did. It helps.

[johnph3]

2 minutes ago, dhe said:

I believe 2-3 should work. Are using this to test  a corcomp rs232? 

Sometimes PDM99 is not so happy with myarc hardware.

Don't have any Myarc hardware only Ti and corcomp. But only have Ti hardware in my PEB at the moment. I wonder if this test on corcomp PDM is looking for Corcomp RS232. Maybe something unique about it that Ti ES232 doesn't have?

[+dhe]

fwiw - PDM99 won't come up if you have a myarc fd in the pbox.

 

 

[johnph3]

So how many versions of RS232 cards did corcomp make. Below is a picture of mine. I was told it is a ver 3 but I am not sure. Any comments.

It is using a 2732 rom.

Edited April 27, 2022 by johnph3

[+Ksarul]

There were several board revisions for the RS-232 card, but all of them work the same way. Most of the changes were to the board's form factor: early boards fit into a metal case, later ones had tabs to slide into the PEB fingers and had no cases.

[ti99iuc]

@Ksarul was the same also for the one in the external CorComp9900?

[johnph3]

So its just a matter if it uses a 2732 rom or a 2764 rom just move the jumper?

[+Ksarul]

On 4/27/2022 at 2:15 PM, johnph3 said:

So its just a matter if it uses a 2732 rom or a 2764 rom just move the jumper?

Correct as far as it goes. The most important item to note is that the jumper you need to change is actually unpopulated on your board (it is the row of three pads to the right of the 2732, near pins 23 and 24). The pads are hardwired to expect a 2732 in the socket (providing +5V to pin 24), but by cutting the trace hardwiring it to that state and putting a three-pin jumper into the pad holes, you can then use a jumper block to select between the two modes of operation. This situation applies to any Revision E board.

 

Prior revisions use different jumpers, but can also select between 2732 and 2764 DSR EPROMs.

 

I figured I'd better note this solution in a public post, as it will help anyone else that has similar DSR recognition problems with a CorComp Revision E RS-232 board in the future. The schematic for this board variant is also in the CorComp schematic archive in the schematics thread.

[johnph3]

Ok still looking for loop back pug pin out to test rs232/1 to rs232/2 on diagnostic disk. 3-14 and 2 to 16 works on #7 test of rs232. But it doesn't work on  the last two test which is rs232/1 to rs232/2 and rs232/3 to rs232/4. Anybody know the correct pins to jumper to get just the first one rs232/1 to rs232/2 to work?