Modem Access?

[vseven]

Have you been able to access a modem through this? I can see the traffic going back and forth but the modem on the physical host doesn't respond nor do I get a response within the VM. I noticed in Virtual PC 2007 there is a "Wait for modem command to open port" if you select the actual physical com port so they must do something "extra". Any ideas?

[albertjan]

Hi yeah I've got it hooked up to a Siemens TC35i (GSM modem) back at work. And it works fine. What do you mean with the modem does not respond? If you open a terminal in the VM and you type "AT" followed by a return do you get "OK\r\n" or not? Because information going back and forth means the namedpipe serialport link works.

[vseven]

The host has a USR 56k External modem installed. You go into the modems properties and hit "Query modem" and you get back a almost instant "cannot communicate". Virtual PC 2007 has a checkbox for modems so that led me to believe it's doing something extra. So I added a Serialport.write("AT") and sleep(500) right after opening the serial port and now I can query it. With that said I still can't dial out of Hyper Terminal from within the VM. If I go to a straight comm port 1 connection and type "AT" and enter I see this go over:

4:45:24 PM - Read: 1 from pipe. Have 0 in buffer.
4:45:24 PM - Read (NP): A
4:45:25 PM - Wrote (CP): A
4:45:25 PM - Read: 1 from pipe. Have 0 in buffer.
4:45:25 PM - Read (NP): T
4:45:25 PM - Wrote (CP): T
4:45:27 PM - Read: 1 from pipe. Have 0 in buffer.
4:45:27 PM - Read (NP): \r
4:45:27 PM - Wrote (CP): \r
4:45:28 PM - Read (CP): \r\nOK\r\n
4:45:28 PM - Block 3
4:45:28 PM - Wrote (NP):\r\nOK\r\n

and I get a valid OK inside Hyper Terminal. But dialing out doesn't seem to work.

I'm looking to hook up a fax modem to my HyperV box that right now is on a aging old machine so that's the primary focus. Secondary is getting a security system to work in a VM that uses a serial port for communication to it's panels.

[albertjan]

Allright I understand. I'll have to look into it.

[albertjan]

So far I've been able to get as far as the PPP authentication in a windows dailup. I think you should leave the checkbox off, so the port gets opened immediately. I've found some additional weird things :) esp. in 0-modem setups. I have a feeling there's a receive buffer that doesn't get emptied often enough. The query modem button works fine for me. It's after the CONNECT 9600 command things appear to stop working. I'll have a look if I can decipher the PPP messages. maybe I'll find what goes wrong.

Sofar I've found out the binary messages get mangled when they are sent to the serial port.

[vseven]

I'm wondering if that checkbox within VPC 2007 is looking at the commands and it's not passing the buffer until it sees the termination ( \r ) then pushes the buffer. Same within VPC 2007....if that check box isn't checked the modem doesn't seem to work but with it checked it works fine. Has to be something with timing there. Going to try and see if I can hold the buffer and wait for the full command then send it, see if that works.

Edit: Little progress. Added a "WaitForModemCommands" setting to mine then added this at the end of the StartCommunication section:

  If My.Settings.WaitForModemCommands Then
       SerialPort.DtrEnable = True
       Thread.Sleep(300)
  End If

Think that's all it really needed. The modem still doesn't "auto" detect but once I select the correct driver within the VM I can use it without issues. Next up is to try faxing with it.

[vseven]

Ok...after some playing I "think" what the check box does is waits for the \n or \r (vbcr or vblf) then forwards what has been buffered so far to the com port. I'm going ot see if I can get a hold of someone on the Microsoft VPC team to answer what it really does.

[albertjan]

I pushed the DTR & CTS enables. That fixes some of the problems i'm still facing some problems with the binary mode. What happens is:
Windows sends:

ATDT0676001234

Modems answers:

CONNECT 9600 //this is where the modem goes into binary mode

Windows answers with: (sent through the named-pipe)

7e ff 7d 23 c0 21 7d 21 7d 20 7d 20 7d 37 7d 22
7d 26 7d 20 7d 20 7d 20 7d 20 7d 25 7d 26 52 58
38 43 7d 27 7d 22 7d 28 7d 22 7d 2d 7d 23 7d 26
ca 7d 36 7e

This is what comes out afaics:

7e ff 7d 23 c0 21 7d 21 7d 20 7d 20 7d 37 7d 7d
26 7d 20 7d 20 7d 20 7d 20 7d 25 7d 26 52 38 43
7d 27 7d 22 7d 28 7d 22 7d 2d 7d 23 7d 26 ca 7d
36 7e 

as you can see I'm missing 2 bytes 2 times the 16th byte (22 and 58) .... took me all morning to find out... And now things become really interesting! The UART buffer is 16 bytes. :)

7e ff 7d 23 c0 21 7d 21 7d 20 7d 20 7d 37 7d **22**
7d 26 7d 20 7d 20 7d 20 7d 20 7d 25 7d 26 52 **58**
38 43 7d 27 7d 22 7d 28 7d 22 7d 2d 7d 23 7d 26 
ca 7d  36 7e 

That said I have no idea how to solve this. I think I have to read quicker from the named-pipe or.. let windows write less quickly to it.

[albertjan]

I think i've done it :) I've googled something over 9600baud via NP2COM :). Turned off all the logging apparently that was causing so much lag, that I wasn't reading the stream quickly enough. I made it double buffering, so there's a buffered stream reading from the named-pipe and I read that and put it in the buffer of the comport to be written. In one version I removed all Thread.Sleeps that wasn't a good one made things terribly slow :). Keep me posten on faxxing, i think there are lots of people that would like to see that working :P.

Ok it wasn't all the logging :P.

Oh and it looks like software compression might not work.

[vseven]

You seem to be having much better luck then I.

So with your revised code (I'm using your logic with my interface as a VB.Net windows application) I start up my VM then start the NP2Com . The first thing I do is open up Control Panel then "Phone and Modem Options" and query the "Standard 56k External Modem" (it's actually a USER 56k ext). The query works and I get the results:

2:50:57 PM - Wrote (CP): ATQ0E0V1\r
2:50:57 PM - Read (CP): \r\nOK\r\n
2:50:57 PM - Wrote (NP):\r\nOK\r\n
2:50:57 PM - Wrote (CP): AT+GCI?\r
2:50:57 PM - Read (CP): \r\nERROR\r\n
2:50:57 PM - Wrote (NP):\r\nERROR\r\n
2:50:59 PM - Wrote (CP): AT\r
2:50:59 PM - Read (CP): \r\nOK\r\n
2:50:59 PM - Wrote (NP):\r\nOK\r\n
2:50:59 PM - Wrote (CP): AT&FE0V1&C1&D2S95=47S0=0\r
2:51:00 PM - Read (CP): \r\nERROR\r\n
2:51:00 PM - Wrote (NP):\r\nERROR\r\n
2:51:02 PM - Wrote (CP): ATE0Q0V1\r
2:51:02 PM - Read (CP): \r\nOK\r\n
2:51:02 PM - Wrote (NP):\r\nOK\r\n

So I then go into Hyper Terminal and have it dial out to my cell phone just to make sure it can do so and it does and works great:

2:55:52 PM - Wrote (CP): AT\r
2:55:52 PM - Read (CP): \r\nOK\r\n
2:55:52 PM - Wrote (NP):\r\nOK\r\n
2:55:52 PM - Wrote (CP): AT&F&D2V1Q0E0S0=0&C1\r
2:55:52 PM - Read (CP): \r\nOK\r\n
2:55:52 PM - Wrote (NP):\r\nOK\r\n
2:55:52 PM - Wrote (CP): AT&A3X4&B1\r
2:55:52 PM - Read (CP): \r\nOK\r\n
2:55:52 PM - Wrote (NP):\r\nOK\r\n
2:55:52 PM - Wrote (CP): AT&A0\r
2:55:52 PM - Read (CP): \r\nOK\r\n
2:55:52 PM - Wrote (NP):\r\nOK\r\n
2:55:52 PM - Wrote (CP): ATS7=60S19=0M1&M4&K1&H1&R2&I0B0X4\r
2:55:52 PM - Read (CP): \r\nOK\r\n
2:55:52 PM - Wrote (NP):\r\nOK\r\n
2:55:52 PM - Wrote (CP): AT\r
2:55:52 PM - Read (CP): \r\nOK\r\n
2:55:52 PM - Wrote (NP):\r\nOK\r\n
2:55:52 PM - Wrote (CP): AT&F&D2V1Q0E0S0=0&C1\r
2:55:53 PM - Read (CP): \r\nOK\r\n
2:55:53 PM - Wrote (NP):\r\nOK\r\n
2:55:53 PM - Wrote (CP): AT&A3X4&B1\r
2:55:53 PM - Read (CP): \r\nOK\r\n
2:55:53 PM - Wrote (NP):\r\nOK\r\n
2:55:53 PM - Wrote (CP): AT&A0\r
2:55:53 PM - Read (CP): \r\nOK\r\n
2:55:53 PM - Wrote (NP):\r\nOK\r\n
2:55:53 PM - Wrote (CP): ATS7=60S19=0M1&M0&K0&H1&R2&I0B1X4\r
2:55:53 PM - Read (CP): \r\nOK\r\n
2:55:53 PM - Wrote (NP):\r\nOK\r\n
2:55:53 PM - Wrote (CP): ATDT8,8888888\r

I pop into a connection directly with COM1 in HyperTerminal and just issue a AT to check and still good:

2:55:52 PM - Wrote (CP): AT\r
2:55:52 PM - Read (CP): \r\nOK\r\n

So I open up the default XP fax software and send myself a fax and it doesn't work plus it seems the modem simply stops responding:

3:10:19 PM - Wrote (CP): AT\r
3:10:19 PM - Read (CP): \r\nOK\r\n
3:10:19 PM - Wrote (NP):\r\nOK\r\n
3:10:19 PM - Wrote (CP): AT&F&D2V1Q0E0S0=0&C1\r
3:10:19 PM - Read (CP): \r\nOK\r\n
3:10:19 PM - Wrote (NP):\r\nOK\r\n
3:10:19 PM - Wrote (CP): AT&A3X4&B1\r
3:10:19 PM - Read (CP): \r\nOK\r\n
3:10:19 PM - Wrote (NP):\r\nOK\r\n
3:10:19 PM - Wrote (CP): AT&A0\r
3:10:19 PM - Read (CP): \r\nOK\r\n
3:10:19 PM - Wrote (NP):\r\nOK\r\n
3:10:19 PM - Wrote (CP): ATS7=60S19=0M1&M4&K1&H1&R2&I0B0X4\r
3:10:19 PM - Read (CP): \r\nOK\r\n
3:10:19 PM - Wrote (NP):\r\nOK\r\n
3:10:19 PM - Wrote (CP): AT#CID=1\r
3:10:19 PM - Read (CP): \r\nOK\r\n
3:10:19 PM - Wrote (NP):\r\nOK\r\n
3:10:19 PM - Wrote (CP): ATS0=0\r
3:10:20 PM - Read (CP): \r\nOK\r\n
3:10:20 PM - Wrote (NP):\r\nOK\r\n
3:10:20 PM - Wrote (CP): ATZ\r
3:10:20 PM - Read (CP): \r\nOK\r\n
3:10:20 PM - Wrote (NP):\r\nOK\r\n
3:10:20 PM - Wrote (CP): AT\r
3:10:21 PM - Wrote (CP): \rAT\r
3:10:21 PM - Wrote (CP): AT\r
3:10:22 PM - Wrote (CP): \rAT\r
3:10:22 PM - Wrote (CP): AT\r
3:10:23 PM - Wrote (CP): \rAT\r
3:10:24 PM - Wrote (CP): AT\r
3:10:25 PM - Wrote (CP): \rAT\r
3:10:25 PM - Wrote (CP): AT\r
3:10:26 PM - Wrote (CP): \rAT\r
3:10:26 PM - Wrote (CP): AT\r
3:10:27 PM - Wrote (CP): \rAT\r
3:10:28 PM - Wrote (CP): AT\r
3:10:29 PM - Wrote (CP): \rAT\r
3:10:29 PM - Wrote (CP): AT\r
3:10:30 PM - Wrote (CP): \rAT\r
3:10:30 PM - Wrote (CP): AT\r
3:10:31 PM - Wrote (CP): \rAT\r
3:10:31 PM - Wrote (CP): AT\r
3:10:32 PM - Wrote (CP): \rAT\r
3:10:33 PM - Wrote (CP): AT\r
3:10:34 PM - Wrote (CP): \rAT\r
3:10:34 PM - Wrote (CP): AT\r
3:10:35 PM - Wrote (CP): \rAT\r
3:10:35 PM - Wrote (CP): AT\r
3:10:36 PM - Wrote (CP): \rAT\r
3:10:37 PM - Wrote (CP): AT\r
3:10:38 PM - Wrote (CP): \rAT\r
3:10:38 PM - Wrote (CP): AT\r
3:10:39 PM - Wrote (CP): \rAT\r
3:10:39 PM - Wrote (CP): AT\r
3:10:40 PM - Wrote (CP): \rAT\r
3:10:40 PM - Wrote (CP): ATE0V1\r
3:10:41 PM - Wrote (CP): \rAT\r
3:10:42 PM - Wrote (CP): ATE0V1\r
3:10:43 PM - Wrote (CP): \rAT\r
3:10:43 PM - Wrote (CP): ATE0V1\r
3:10:44 PM - Wrote (CP): \rAT\r
3:10:44 PM - Wrote (CP): ATE0V1\r
3:10:45 PM - Wrote (CP): \rAT\r
3:10:45 PM - Wrote (CP): ATE0V1\r
3:10:46 PM - Wrote (CP): \rAT\r
3:10:47 PM - Wrote (CP): ATE0V1\r
3:10:48 PM - Wrote (CP): \rAT\r
3:10:48 PM - Wrote (CP): ATE0V1\r
3:10:49 PM - Wrote (CP): \rAT\r
3:10:49 PM - Wrote (CP): ATE0V1\r
3:10:50 PM - Wrote (CP): \rAT\r
3:10:51 PM - Wrote (CP): ATE0V1\r
3:10:52 PM - Wrote (CP): \rAT\r
3:10:52 PM - Wrote (CP): ATE0V1\r
3:10:53 PM - Wrote (CP): \rAT\r
3:10:53 PM - Wrote (CP): ATE0V1\r
3:10:54 PM - Wrote (CP): \rAT\r
3:10:54 PM - Wrote (CP): ATE0V1\r
3:10:55 PM - Wrote (CP): \rAT
3:10:55 PM - Wrote (CP): \r
3:10:56 PM - Wrote (CP): ATE0V1\r
3:10:57 PM - Wrote (CP): \rAT\r
3:10:57 PM - Wrote (CP): ATE0V1\r
3:10:58 PM - Wrote (CP): \rAT\r
3:10:58 PM - Wrote (CP): ATE0V1\r
3:10:59 PM - Wrote (CP): \rAT\r
3:11:00 PM - Wrote (CP): ATE0V1\r
3:11:01 PM - Wrote (CP): \rAT\r
3:11:01 PM - Wrote (CP): AT\r
3:11:02 PM - Wrote (CP): \rAT\r
3:11:02 PM - Wrote (CP): AT\r
3:11:03 PM - Wrote (CP): \rAT\r
3:11:03 PM - Wrote (CP): AT\r
3:11:05 PM - Wrote (CP): AT\r
3:11:07 PM - Wrote (CP): AT\r

And then the fax program times out with a error AND seems to lockup the modem...I can no longer use HyperTerminal and get any replies from it. HOWEVER if I go into the Phone and Modem Options and do a Query Modem the modem replies and then starts working correctly in HyperTerminal again. I tried getting rid of the Thread.Sleep commands completely and it made the query modem much faster but made sending commands through Hyper Terminal spotty. Really thinking that the commands have to be queued but not sur e(like look for a "A" then if found hold the buffer and wait for the next character and if it's a "T" then wait again and wait until a vbcr or vblf but I could be completely wrong).

I did email some of the Virtual PC guys and asked what they are doing in that Wait for Modem checkbox but I don't know if they will get back with me or even be able to tell me.

[albertjan]

it looks a bit like your modem is reset to a state that expects some different communications with the ATZ command. I'll check the usr tech manuals tomorrow and see if there is some clue to be found. I only have gsm modems to test with atm but i do have a laptop with a modem i'll try to get the fax software working on that with vpc and xpmode. you could try so sniff the com port at the host with comport listen software like hdd makes. maybe that'll give you some hints. have you tried dialing up to an isp? i wonder if that works. there are also generic modem drivers in windows i use those, maybe they are a bit less bitchy. good luck.

[albertjan]

Hey vseven, the check box is disabled in newer versions of VPC for named-pipe connections. It's only available for direct com2com connections. Which have as you know disappeared from hyperv. I've today sent and received a fax on VirtualPC on windows seven with xp in a vm. I again used the generic modem drivers in windows they work fine.

[vseven]

I've tried both the "Standard 56000 modem" driver and the actual "USR 56k EXT FAX" with the same results, the modem appears to "lock up".

So I kept looking at this USR 56k modem that has a row of dip switches on the back. I know it keeps locking up so I look to see if any dip switches would affect that. Turns out a a dip switch for "Suppress Result Codes" was set to on. Turned that off (so result codes are given) and I got the modem to fax successfully using the direct COM port method of the VPC 2007 but still not through the NP2COM program. It does initialize and dial out but gets lost during the transmission. I'm going to play with enabling/disabling compression, slowing the buad rate down, etc, and see what happens.