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Host: Windows XP SP3
Guest: Windows XP SP3
Virtual PC 2007 (6.0.156.0)

I have two serial devices attached to the host (chip and pin card readers). These work with my application when running on the host.

On the guest OS, I have mapped virtual COM ports to the physical ones and these show up in Device Manager.

I am unable to download config data to the devices. SysInternals PortMon on the guest allows me to see data being sent:

ddl.exe IRP_MJ_CREATE Serial0 SUCCESS Options: Open
ddl.exe IOCTL_SERIAL_SET_WAIT_MASK Serial0 SUCCESS Mask:
ddl.exe IOCTL_SERIAL_GET_BAUD_RATE Serial0 SUCCESS
ddl.exe IOCTL_SERIAL_GET_LINE_CONTROL Serial0 SUCCESS
ddl.exe IOCTL_SERIAL_GET_CHARS Serial0 SUCCESS
ddl.exe IOCTL_SERIAL_GET_HANDFLOW Serial0 SUCCESS
ddl.exe IOCTL_SERIAL_GET_BAUD_RATE Serial0 SUCCESS
ddl.exe IOCTL_SERIAL_GET_LINE_CONTROL Serial0 SUCCESS
ddl.exe IOCTL_SERIAL_GET_CHARS Serial0 SUCCESS
ddl.exe IOCTL_SERIAL_GET_HANDFLOW Serial0 SUCCESS
ddl.exe IOCTL_SERIAL_SET_BAUD_RATE Serial0 SUCCESS Rate: 57600
ddl.exe IOCTL_SERIAL_SET_RTS Serial0 SUCCESS
ddl.exe IOCTL_SERIAL_SET_DTR Serial0 SUCCESS
ddl.exe IOCTL_SERIAL_SET_LINE_CONTROL Serial0 SUCCESS StopBits: 1 Parity: NONE WordLength: 8
ddl.exe IOCTL_SERIAL_SET_CHAR Serial0 SUCCESS EOF:0 ERR:0 BRK:0 EVT:0 XON:11 XOFF:13
ddl.exe IOCTL_SERIAL_SET_HANDFLOW Serial0 SUCCESS Shake:1 Replace:40 XonLimit:2048 XoffLimit:512
ddl.exe IOCTL_SERIAL_SET_TIMEOUTS Serial0 SUCCESS RI:0 RM:0 RC:0 WM:0 WC:0
ddl.exe IRP_MJ_WRITE Serial0 SUCCESS Length 1: .
ddl.exe IOCTL_SERIAL_SET_TIMEOUTS Serial0 SUCCESS RI:-1 RM:0 RC:0 WM:0 WC:0
ddl.exe IRP_MJ_READ Serial0 SUCCESS Length 0:
ddl.exe IRP_MJ_WRITE Serial0 SUCCESS Length 1: .
ddl.exe IOCTL_SERIAL_SET_TIMEOUTS Serial0 SUCCESS RI:-1 RM:0 RC:0 WM:0 WC:0
ddl.exe IRP_MJ_READ Serial0 SUCCESS Length 0:

The devices just sit perpetually waiting for data.

Any ideas how to troubleshoot further?

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migrated from serverfault.com Mar 22 '11 at 16:22

This question came from our site for system and network administrators.

up vote 0 down vote accepted

Found the devices were hard-coded to communicate at 115,200 baud and do not negotiate speed. Once I changed from 57,600 baud, all was well.

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