id summary reporter owner description type status component version resolution keywords cc guest host 8964 Software problem with serial port Nike_spb "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." defect closed uart VirtualBox 4.0.6 obsolete serial port Windows Windows