Help with faulty rs232 debugging steps

[mTeryk]

I've had my FP2NC with Dialog 4 for quite awhile since I got it from Ross maybe 8 years ag. File transfer has been working fine the whole time. I use DNC4U to transfer files from either my PC with a native com port or a small mini PC using a USB com port. A few months ago I noticed that I couldn't download files from the Deckel to the mini PC and figured it might have been due to a software update. Didn't troubleshoot it as I rarely need to copy programs from the Deckel. After not using the machine for awhile, I went to transfer a program over yesterday and file transfer is totally broken. Can't transfer files to or from using either my PC or the mini PC. There is no error reported. When trying to transfer files to the machine it just waits forever and never appears to see data. When sending data out, it just immediately returns. Don't see it sending any data out.

Nothing about the cable or connectors has changed. Both computers have seen many Windows updates but the settings for the com ports remain the same. I've pulled and reset each board in the control and there is no visible corrosion. I did a hard reset using the K10 jumper and reset my rs232 settings (4800baud, 7 bits,1 stop bit, no parity) and there is no difference.

There are 2 solid red leds on either side of what I believe is the serial connector coming into the NPP54 board. Is that a sign of an error?

Looking for suggestions on what to check next to localize the problem.

Thanks

 

[Colt45]

The connector you have circled is for the "PC" in the outboard cabinet. The LEDs on either side indicate good "send/receive" to the PC and should be lit when things are normal. K11 connects to the RS232 port on the bottom of the console (thx Ross).

In my experience, USB-RS232 adaptors can be problematic but I would triple check your RS232 settings on the computer. Check if those settings are available in more than one place on the computer- there is a place in your computer OS as well as your communications program. Sometimes your settings get changed in an update, maybe in a place on the computer you don't expect. Make sure you have the correct "port" designated. Might want to also check your cable, especially that the connectors are still making good contact.

 

[AlfaGTA]

Actually i believe that K11 is the connection to the RS232 port and it connects to the NSI board (slot 11)
Think if i am not mistaken K7/8 connect to the MPG.(Dialog4)
Power off the machine (main)
Remove each board from the chassis (one at a time) No need to do the NZP boards (axis boards or the power supply NSV)
Lay each board down on a flat wooden surface and firmly press down on each socketed IC to make sure they are seated.
Thermal changes (on/off) can cause the chips to move in their sockets.....
Restart and try your transfer again.

Cheers Ross

 

[mTeryk]

The connector you have circled is for the "PC" in the outboard cabinet. The LEDs on either side indicate good "send/receive" to the PC and should be lit when things are normal. K11 connects to the RS232 port on the bottom of the console (thx Ross).

Arg! I forgot that PC refers to the high voltage cabinet not the personal computer. Thanks

In my experience, USB-RS232 adaptors can be problematic but I would triple check your RS232 settings on the computer. Check if those settings are available in more than one place on the computer- there is a place in your computer OS as well as your communications program. Sometimes your settings get changed in an update, maybe in a place on the computer you don't expect. Make sure you have the correct "port" designated. Might want to also check your cable, especially that the connectors are still making good contact.

Yep, I know. That is why I initially suspected a driver update on the Mini PC but the fact that it behaves the same with my workstation that has native com ports seems to eliminate that possibility. I have the ports and settings correct in both dnc4u and Device Manager so I highly doubt it is a problem on the computer side of things. Not impossible, though. Thanks for the suggestions.

 

[mTeryk]

Actually i believe that K11 is the connection to the RS232 port and it connects to the NSI board (slot 11)
Think if i am not mistaken K7/8 connect to the MPG.(Dialog4)
Power off the machine (main)
Remove each board from the chassis (one at a time) No need to do the NZP boards (axis boards or the power supply NSV)
Lay each board down on a flat wooden surface and firmly press down on each socketed IC to make sure they are seated.
Thermal changes (on/off) can cause the chips to move in their sockets.....
Restart and try your transfer again.

Cheers Ross

Thanks for the pointer to K11 and the NSI board. That should give me a place to start. I already removed each board and pressed on the socketed ICs. I'll try that again, however.

Thanks

 

[HLudlum]

I've had my FP2NC with Dialog 4 for quite awhile since I got it from Ross maybe 8 years ag. File transfer has been working fine the whole time. I use DNC4U to transfer files from either my PC with a native com port or a small mini PC using a USB com port. A few months ago I noticed that I couldn't download files from the Deckel to the mini PC and figured it might have been due to a software update. Didn't troubleshoot it as I rarely need to copy programs from the Deckel. After not using the machine for awhile, I went to transfer a program over yesterday and file transfer is totally broken. Can't transfer files to or from using either my PC or the mini PC. There is no error reported. When trying to transfer files to the machine it just waits forever and never appears to see data. When sending data out, it just immediately returns. Don't see it sending any data out.

Nothing about the cable or connectors has changed. Both computers have seen many Windows updates but the settings for the com ports remain the same. I've pulled and reset each board in the control and there is no visible corrosion. I did a hard reset using the K10 jumper and reset my rs232 settings (4800baud, 7 bits,1 stop bit, no parity) and there is no difference.

There are 2 solid red leds on either side of what I believe is the serial connector coming into the NPP54 board. Is that a sign of an error?

Looking for suggestions on what to check next to localize the problem.

Thanks

View attachment 367515

I know this is a very old post, but I felt compelled to reply. The RS-232 communications to and from various controls involves different ACK NAK handshaking. Some machines will simply swallow anything that comes down the pike to them, so you better have things on both ends to be ready. Others have to complete a handshake. In 1986 I worked with a little known DNC product that Applicon had called BravoDNC. I used a Data Analyzer to see what communications was going on so that I could write the formatter for a given machine. Huston

 

[rimcanyon]

Yes it is an old post, but I just went through this after upgrading my FP2NC to D4 and wanting to get serial comms working. After several attempts that did not succeed, I figured that I had too many variables in the setup. So to eliminate the PC end (actually MACbook in my case), I connected the USBC port on the MAC to a USB port on a PC, using a pair of serial port cables with a DB9 connectors. That combination was much easier to get working, and I found that I needed a null modem to get it to work. So once I had a working Mac USBC to DB9 connection, getting the Mac to talk to the D4 control was easy.

 

[HLudlum]

That's Cool. After I sent my post, I though I should have mentioned a 'Null Modem' cable Transmit and Receive pins are crossed. Otherwise you are only talking to yourself.
By the way, you have been on here for quite some time. I am looking for an 80's vintage PC with a 5 1/4 floppy drive on it. I have quite a few 5 1/4 floppy disks downstairs. I want to copy all the files off and trash the disks. Have you ever seen anyone selling an 80's vintage PC on this site. In 2018, when i was moving one of the movers dropped my Corona Luggable PC w/2 5 1/4 drives on it. After a lot of cussing, i was so pissed that I just threw the damn thing in the trash

Huston

 

[rimcanyon]

I have a similar problem, but using the later 3 1/2 floppies. You don’t need a vintage PC - just get an external floppy drive with a USB port, and you can read them on a modern PC or Mac.

 

[HLudlum]

Sounds good, but I just can’t find one. I have two drives, but the bios in these new pc’s just won’t recognize them. The bios may not even recognize the drive on a USB Interface. I have searched for External USB 5 1/4 drives to no avail.
Thanks
Huston

 

[rimcanyon]

I looked too, could not find anything except 5.5" drives that use the internal parallel cable. You may need to get a PC from the early 2000's...