Serial Card Woes

[LesAuber]

This is a bit of a long story that started with blowing up my CQC MS. As part of the repair the system was upgraded to Win 7 Pro. A consequence of this was needing a new serial card as the old one wouldn't work under Win 7. SIIG supposedly has drivers but they wouldn't install.

The new card is an 8 port Startech. It installs properly and WDM thinks it's all working. However, it doesn't seem possible to get a connection with this card. CQC will go in a cycle of trying to get comm resource, got comm resource, try to communicate, fail and then lose the comm resource. Over and over. I've tried reinstalling the card along with the latest available drivers to no effect.

Trying a terminal utility and watching port status it seems like it connects but no communication is possible. Rather frustrating.

The two serial ports on the mother board work fine. No issues. One thing I noticed is these ports have the option of no flow control while the new card does not. I'd expect the manifest to overwrite this but.

Dean and I have been chasing this thing for a little while now with no joy so thought we'd throw it out to see if anyone else had ideas.

[Dean Roddey]

The logs would seem to indicate an inability to write data, which typically is hardware flow control related. I guess one way to test it is to use a three wire on one of them to see if that makes it happy. If so, then definitely it would prove that the low level driver is using hardware flow control even if told not to do so by the driver, since a three wire cable would not be able to pass the flow control signals.

[LesAuber]

Let me give that a try. I should have a couple adapters around that aren't assembled. Easy enough to only install 3 pins.

What I don't understand though is why it would matter. Most of my equipment only uses 3 pins. Could it be looking for a response that isn't possible on flow control?

[Dean Roddey]

The full cable will pass along all flow control signals. If one of them is, for whatever reason, telling the other side "I'm not ready to receive" the windows serial port code won't send, and the send will time out. With the three wire cable, they can't see each other's flow control lines, so they won't/can't stop the other side form sending in that way.

By default, if the manifest doesn't say otherwise, the flow control lines will be set up to disable (ignore really) hardware flow control, i.e. always say I'm ready to receive, so you can send. If, for some reason, that is being ignored, it could leave you back in the first type of scenario. Doesn't mean that the other side will work, but if you don't see the timeout on the send, then that will mean that it was being prevented from sending by the hardware flow control since that'll be the only thing that changed.

[LesAuber]

I made up a connector with only pins 2, 3, and 5. Short story, no joy. Works find on Comm 1 but won't connect on any of the expansion card ports.

I thought I might have found a solution when I found and unchecked a 'use default BAUD rate' check box in the port settings but no luck there either.

If there are no other ideas I could try Startech tech support but my experience with most vendors varies from bad to pathetic.

[Dean Roddey]

It's probably worth at that point just picking up an Edgeport box perhaps, or a newer SIIG card. Maybe you can return the Startech?

[LesAuber]

Edgeport is good? No experience.

I'll give SIIG another look. The card I had worked well. Got a bit down on them when their Win 7 drivers wouldn't work despite the claim. I'll have to give a manual install a try.

I'll have to check with NewEgg on return. I forget what the policy is.
Thanks,

[potts.mike]

I got an edge port off eBay a few years ago and it works flawlessly.

[LesAuber]

Thanks, flawless is what I'm after.