#8964 closed defect (obsolete)
Software problem with serial port
| Reported by: | Nike_spb | Owned by: | |
|---|---|---|---|
| Component: | uart | Version: | VirtualBox 4.0.6 |
| Keywords: | serial port | Cc: | |
| Guest type: | Windows | Host type: | Windows |
Description (last modified by )
Hello! My host is Win 7 64b, Intel Core i5 2400 3.1 GHz, 4 Gb RAM. I have successfully set up serial port on my vm (Win XP 32b) as described in different topics: Port1: Checked Port Number: COM1 (also tried COM2, COM3, COM4) Port Mode: Host Device Port/File Path: COM1 (tried others, see further)
The problem is in connecting to devices via com port. It's not a physical problem, because I've tried to use pci2com controller, usb-rs232 adapter and on-board com port. Settings are: 9600 / 8 / odd / 1 / no flow control. I have to use a monitoring program to log what's happening with com port (see all attachments, except vbox.log). I have used 2 different programs OIL-DS 1.3, T-PDS32 for Windows 2.21. OIL-DS 1.3 always works fine. T-PDS32 doesn't work.
Why is this a virtualbox problem?
1) T-PDS32 works great on any other PC (not virtual)
2) T-PDS32 establishes a connection with a PLC after the settings of the com port have been reset by downloading (or trying to) something via this port by another software - OIL-DS. My guess is that it somehow resets port's parameters and after that T-PDS can work for some time. After reconnecting - again connection problem. See the log file tpds_oil_tpds.txt - there I've tried to connect using T-PDS (no success), then OIL-DS, then T-PDS again (successfully).
3) I've tried to establish the connection with com port using OIL-DS both on host and on vm using exactly the same settings. The behaviour is different (see host_log and vm_log files).
In whole I think that means:
1) it's a software problem
2) virtualbox somehow modifyes the data which is send to com port (and in result some programs can work unstable)
Looking forward to your help. Thank you.
Attachments (4)
Change History (7)
by , 13 years ago
by , 13 years ago
| Attachment: | tpds_oil_tpds.txt added |
|---|
Trying to connect using T-PDS - OIL-DS - T-PDS
comment:2 by , 8 years ago
| Description: | modified (diff) |
|---|---|
| Resolution: | → obsolete |
| Status: | new → closed |
Please reopen if this is still relevant with a recent VirtualBox release.
comment:3 by , 7 years ago
This, unfortunately, is still a major issue running VirtualBox 5.x under Windows 10 (64). Data is lost and/or stuck, and the "COM port" handling is sensitive to XON/XOFF (software flow control). All applications in the chain are requesting ONLY hardware flow control (CTS/RTS) and the machine is way powerful. Running the exact same set-up under VMware Workstation Player 12 works great. Windows 10 Host, FreeDOS Guest, FOSSIL (COM) driver in FreeDOS, NetSerial (Virtual Modem) in Windows.
vbox log