COM Port Designation in 3.0

[southpeoria]

Installed PCAccess 3.0 a couple of weeks ago and just noticed that when I select Options>Serial, the default COM port is displayed in lower case as "com1", while scrolling down displays correctly in upper case as COM3 and COM4. I looked through the registry and did not find any port referrences in lower case...any particular reason why "com1" would appear that way? Anyone else notice that?

Thanks

 

[ricks]

I just installed the V3 chip and PC Access 3 and have a connection issue (unexpected error (53)). I noticed the same thing and assumed, based on my setup, that capitalized port listings are avaialble ports and lower case are unavailable ports. Just a guess, though. Now to find what unexpected error (53) means. Maybe if it were an "expected" error :blink: there would be more detail.

 

[southpeoria]

I just installed the V3 chip and PC Access 3 and have a connection issue (unexpected error (53)). I noticed the same thing and assumed, based on my setup, that capitalized port listings are avaialble ports and lower case are unavailable ports. Just a guess, though. Now to find what unexpected error (53) means. Maybe if it were an "expected" error :blink: there would be more detail.

I don't think it relates to available or unavailable ports, because the only port available for serial communications listed in Device Manager is COM1. That same "com1", in lower case, designation is listed in the modem options as the modem port. So it seems that something in PCA3 may be changing the designation from upper to lower case...question would be...why?

 

[HAI_fjh]

PC Access 2 does the same thing... It is an indication of whether the port is in use or not.

Everything you ever wanted to know about com ports but were afraid to ask:

In the older versions of PCA2, there were only COM1-4, then users needed to access ports higher than 4, so it was extended to COM8. In these versions this was just a dumb pick list with no validation of which ports actually existed or where available. Also users with USB to serial adapters were getting port numbers above 8 and sometimes the port number would change when plugging the adapter into a different USB port...

So I think it was around version 2.12 or possibly 2.14 we made the port selector smarter. It now iterates through all possible ports between 1 and 99 and tries to open the port. If the operation is successful the port is added in upper case indicating that the port exists and is not in use. If there is an error opening the port we look at the specific error. If the error is that the port is in use, or access denied the port is added to the list, but in lower case to indicate that the port exists but is in use. If the error is a "not found" error the the port does not exist and we move on the to the next one.

This was done to help users to identify which ports actually exist and if they were available for use. A common problem is that FAX software, dial up networking, caller ID, or other application grabs the Modem port so PC Access can't use it.

The case that is displayed in the list has no effect on the internal device name or function.

Note that if PC Access is using the port it will appear in lower case also.

The unexpected error is a fall through error. For example when I try to open the port, if an error occurs I check for "expected" errors, like unable to open port, port doesn't exist, insufficient memory, etc. These are common sorts of things that can prevent the port from opening, and creating buffers, etc. If the error is something else, it falls through to the "unexpected error" routine. There are 52 error conditions that we look for and handle, but occasionally we still get errors with error codes that don't make sense.

If you are having communications you should contact technical support. It is free and they have a lot of experience.

 

[southpeoria]

PC Access 2 does the same thing... It is an indication of whether the port is in use or not.

Everything you ever wanted to know about com ports but were afraid to ask:

In the older versions of PCA2, there were only COM1-4, then users needed to access ports higher than 4, so it was extended to COM8. In these versions this was just a dumb pick list with no validation of which ports actually existed or where available. Also users with USB to serial adapters were getting port numbers above 8 and sometimes the port number would change when plugging the adapter into a different USB port...

So I think it was around version 2.12 or possibly 2.14 we made the port selector smarter. It now iterates through all possible ports between 1 and 99 and tries to open the port. If the operation is successful the port is added in upper case indicating that the port exists and is not in use. If there is an error opening the port we look at the specific error. If the error is that the port is in use, or access denied the port is added to the list, but in lower case to indicate that the port exists but is in use. If the error is a "not found" error the the port does not exist and we move on the to the next one.

This was done to help users to identify which ports actually exist and if they were available for use. A common problem is that FAX software, dial up networking, caller ID, or other application grabs the Modem port so PC Access can't use it.

The case that is displayed in the list has no effect on the internal device name or function.

Note that if PC Access is using the port it will appear in lower case also.

The unexpected error is a fall through error. For example when I try to open the port, if an error occurs I check for "expected" errors, like unable to open port, port doesn't exist, insufficient memory, etc. These are common sorts of things that can prevent the port from opening, and creating buffers, etc. If the error is something else, it falls through to the "unexpected error" routine. There are 52 error conditions that we look for and handle, but occasionally we still get errors with error codes that don't make sense.

If you are having communications you should contact technical support. It is free and they have a lot of experience.

Thanks very much for explaining how the port designations work. It all makes sense now. And "yes", the folks in Tech Support have been and continue to be very knowledgeable and helpful.