Nixay Posted November 4, 2013 Posted November 4, 2013 For the last 5 years my show PC has been an older Pentium 4 with 2x on-board serial ports which connected to my two LOR networks using the older SC485-RJ45 serial adapters. I've preferred using actual serial ports due to problems I had with reliability using the USB adapter. This setup worked flawlessly - rock solid. This year I've upgraded my show PC to a newer model which only had 1x on-board serial port, so I went out and bought a PCI-e expansion card to give me another 2x serial ports. Problem is I just can't get these ports to communicate properly with my controllers. Usually the blinking red lights on the controllers go steady within 1-2 secs of starting the hardware utility, but my new setup takes 20-30 secs for the lights to go steady, and scanning the network in this time produces random gibberish in the hardware utility - "unknown controller" and version numbers ???? and the like. And the lights aren't behaving - random things turning on and off. Are there any tips for the com port settings in Windows Device Manager? Default is 9600 baud, data bits 8, parity none, stop bits 1, flow cont. none. I thought 9600 baud was a bit slow? So I pushed it up to 115200, but this hasn't improved things. Not sure if there's an odd compatibility problem with the card I bought which makes it not communicate like standard serial ports? I briefly tested the single on-board serial port and it seemed to work normally, but didn't test for long enough yet to prove it faultless. Nixay
bob Posted November 4, 2013 Posted November 4, 2013 This is a total shot in the dark, but: Maybe the PCI card is not well-seated? Or possibly the cables are not sufficiently isolated/protected against EMF?
Nixay Posted November 4, 2013 Author Posted November 4, 2013 Hmm, that's a possibility. It's a low profile card, so the two 9-pin sockets don't fit on the back. Instead there's a 25-pin D-sub with a breakout cable to two 9-pins. Maybe there's a problem in there....
a31ford Posted November 6, 2013 Posted November 6, 2013 Hi guys, many a com-port add-in board is what's know as a spike in board, that is, the board does NOT really follow the true com port connections but rather "EMULATES" the appearance of a pair of com ports, see, in REAL dos, Com 1 and 3 share the same IRQ, and com 2 & 4 another shared IRQ, these spike in board, rarely use the real IRQ's they literally "Spike" into the higher 12-15 IRQ area, and share with other stuff like video, HDD controllers, even the IRQ polling IRQ 12 (which is also used for the mouse in windoze.... (spelt correctly) zzzzzzz........... I have a couple of the old TRUE comm port boards but in what box of junk, I have no idea (would be weeks of looking through out-buildings to find them). Find a computer shop that "has been around for a while" and ask for a commport board that works in DOS, (has jumper settable IRQ's) this will most-likely be an older ISA board, so if your computer does not have a standard ISA slot, then you are most likely going to have to use the USB 485 controller.... (YUCK).... Greg
Nixay Posted November 12, 2013 Author Posted November 12, 2013 Yeah, that's making some sense. This expansion card is using IRQ 16. Interestingly, I have two networks - one which is predominantly CMD-16D cards, and the other having 4x CCRs - I've moved the CMD-16D network back to the motherboard's only on-board socket (which is working great) and left the CCRs on Com 4 on the expansion card. The CCRs seem to be working fine with it, it looks like only the CMD-16D cards were getting cranky. More testing to be done still but it looks to me like the CCRs are interacting differently. Nixay.
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