Registry and Group Policy Settings (GPO)

It is strictly recommended for non-administrative users to change all settings via Serial Port for Remote Desktop user interface.

Local Settings can be overwritten by program GUI and vice versa. In order to avoid overriding, it's possible to configure the LockConfig registry key. As a result, the user cannot change the settings using tray context menu. Anyway, it will be still possible to change the program settings directly in the HKCU section of the Registry.

Serial Port for Remote Desktop (Server) includes *.admx and *.adml administrative template files. You can use these template files to configure Local GPO and/or Domain-Based GPO. Archive file containing administrative templates can be found in the installation directory:
%ProgramFiles%\FabulaTech\Serial Port for Remote Desktop (Server)\policies.zip

The *.admx/*.adml files are for use with Windows Vista/Windows Server 2008 and all later versions of Windows. Refer Microsoft MSDN article on managing ADMX files.

Name Type Range Default Description
Local: HKCU\Software\FabulaTech\Serial Port for Remote Desktop\Workstation\
Local: HKLM\Software\WOW6432Node\FabulaTech\Serial Port for Remote Desktop\Server\
LogLevel DWORD 0-4 3 0 - Errors
1 - Warnings
2 - Information
3 - Debug
4 - Dump.
RotationLogFileNumber DWORD 0-99 10 When a particular log file reaches a size limit, the program initiates log file rotation, i.e. it renames the existing log file and creates the new one.
If 0, no rotation will take place, unlimited number of log files.
If N, delete oldest log file when N log files already exists.
OverrideLogMaxFiles DWORD 0-4294967295 150 There can be several log files for every user, depending on Session ID, PID, etc. This setting specifies the maximum number of log files of specific component for every user. The number of users is not limited. So all of them will log the activity, but every user is limited in the total number of log files.
If 0, older log files will not be removed.
If N, older log files will be removed once specified limitation is reached.
GPO: HKLM\Software\Policies\FabulaTech\Serial Port for Remote Desktop Server\Settings\
GPO: HKCU\Software\Policies\FabulaTech\Serial Port for Remote Desktop Server\Settings\
LocalSettingsPriority DWORD 0,1 0 1 - the local program settings have priority over policy settings.
0, or not configured - policy settings have priority over local program settings.
Within the scope of each type of settings, the settings set for the computer always have priority over settings set for the user.
If this policy setting is set for the computer, it has priority over policy setting set for the user.
GPO: HKLM\Software\Policies\FabulaTech\Serial Port for Remote Desktop Server\Settings\
Local: HKLM\Software\WOW6432Node\FabulaTech\Serial Port for Remote Desktop\Server\Settings\
Disabled DWORD 0,1 0 1 - the connection with the workstation side is not established, the ports are not redirected and the tray menu icon is not present.
0 - the Serial COM works in usual mode.
Not configured - the disabling functionality is determined by local program settings.
BandwidthLimit DWORD 0-2*1024*1024 0 If this policy setting is enabled, the data transfer speed between the server and all workstations is limited by the specified kilobytes per second. The value "0" disables speed limitation.
0 - the speed limitation is disabled.
Not configured - the speed limitation is determined by local program settings.
ConnectAll DWORD 0,1 0 Connect all ports automatically.
If this policy setting is enabled, all client COM ports will be automatically connected (even if no individual GPO is configured). If there are individual GPO settings configured for some of the ports, the individual port GPO settings are used.
If this policy setting is disabled or not configured, the auto-connect functionality is determined by individual port GPO or local program settings.
IsolatePorts DWORD 0,1,2 0

0 - Isolation Disabled
1 - Full Isolation
2 - Strict Isolation

If "Full Isolation" mode is chosen, virtual serial ports are visible and accessible within user sessions only. In this mode COM port names can have the same names in different user sessions. Important: system services (like spoolsrv.exe) are not able to access isolated serial ports in such case.

If "Strict Isolation" mode is chosen, virtual serial ports are visible and accessible within user sessions and only withing the processes run under the owner of the session. This means that the processes started using "Run as Administrator", or the processes started using PsExec utility will not be able to see and access the redirected serial ports.

If "Isolation Disabled" mode is chosen, virtual serial ports are visible globally. Any port can be accessed from any session. Limitation: port names must be unique for every user (so the ports cannot have the same names in different user sessions). Important: system services (like spoolsrv.exe) can access any serial ports.

If this policy setting is not configured, Serial Redirection operates in the default mode:
- If Terminal Services is installed, "Full Isolation" mode is applied.
- If Terminal Services is not installed, "Isolation Disabled" mode is applied.

GPO: HKLM\Software\Policies\FabulaTech\Serial Port for Remote Desktop Server\Settings\
GPO: HKCU\Software\Policies\FabulaTech\Serial Port for Remote Desktop Server\Settings\
Local: HKLM\Software\WOW6432Node\FabulaTech\Serial Port for Remote Desktop\Server\Settings\
Local: HKCU\Software\FabulaTech\Serial Port for Remote Desktop\Server\Settings\
LockConfig DWORD 0,1 0 1 - the user interface containing the program settings is locked and the user can't change settings in the tray menu.
0 - the user interface containing the program settings is accessible for users.
Not configured - the blocking of the configuration is determined by local program settings.
If this policy setting is configured for the computer, it has priority over policy setting configured for the user.
Local: HKLM\Software\WOW6432Node\FabulaTech\Serial Port for Remote Desktop\Server\Settings\PortSettings\[xxx]\
Local: HKCU\Software\FabulaTech\Serial Port for Remote Desktop\Server\Settings\PortSettings\[xxx]\
CreateOverlappedIfRequired DWORD 0,1 1 1 - create overlapped virtual port if existing CorrespondingVirtualPort exists on machine.
GPO: HKLM\Software\Policies\FabulaTech\Serial Port for Remote Desktop Server\Settings\PortSettings\PortSettings[1-5]\
GPO: HKCU\Software\Policies\FabulaTech\Serial Port for Remote Desktop Server\Settings\PortSettings\PortSettings[1-5]\
Local: HKLM\Software\WOW6432Node\FabulaTech\Serial Port for Remote Desktop\Server\Settings\PortSettings\[xxx]\
Local: HKCU\Software\FabulaTech\Serial Port for Remote Desktop\Server\Settings\PortSettings\[xxx]\
SrcPortNum DWORD 1-256 required "Source port number" - Number of the COM port redirected from the workstation side (e.g. 2 means COM2).
SrcPortDevice String empty "Source Port Device" - Name of Serial port device redirected from the workstation side (e.g. "COM5" for Windows, or "/dev/ttySerial0" for Linux. This paramerter has higer priority than Source port number.).
DstVirtPortNum DWORD 1-256 required or -1 for "port automapping mode" "Destination virtual port number" - virtual COM port number, created on the server side and corresponding to the COM port on the workstation side.
Autoconnect DWORD 0,1 0 "Autoconnect" - If this flag is set, the port is automatically redirected to the server side when it plugged on the workstation side.
IgnoreDsr DWORD 0,1 0 "IgnoreDsr" - If this flag is set, the DSR signal is ignored.
PauseBeforeClosePort DWORD 0-3000 0 "Pause before close port" - Troubleshooting setting. Time (in ms) to wait after virtual COM port was closed by user. Required for some USB-COM adapters.
UsePauseBeforeSendData DWORD 0,1 0 "Use pause before send data" - If this flag is set, pause before send data after port opening will use. See value "Pause before send data".
PauseBeforeSendData DWORD 0-5000 0 "Pause before send data" - Troubleshooting setting. Time (in ms) to wait before virtual COM port will transfer data to physycal side. Required for some specific serial devices (Olivetti card reader).
Serial2USBModeChangeEnabled DWORD 0,1 0 Troubleshooting setting. Disables Overlapped Mode when communicating with hardware COM ports. This allows to overcome specific issues of GlobalSat BU353 GPS adapter (and some other Prolific USB-COM adapters).
DisableErrorsInWaitMask DWORD 0,1 0 "Disable errors in wait mask" - Troubleshooting setting. Disables "error" value in serial COM mask. See this article for details. Required for some software.
HandleBtDisappear DWORD 0,1 0 Troubleshooting setting. It handles the situations when Bluetooth COM ports disappear suddenly on the Client side (because the Bluetooth device gets out of range) and then appear again.
UsbToComTroubleShooting DWORD 0,1 0 Troubleshooting setting. Fixes some specific issues of USB-COM adapters.
UseTimeoutsMultiplicator DWORD 0,1 0 "Use network latency compensation" - Troubleshooting setting. Use compensation capability to avoid influence of network delays.
TimeoutsMultiplicator DWORD 1-10 0 "Compensation level" - Troubleshooting setting. Using spinedit, select network latency compensation level. Find out the minimal level at which your communications application works stable with a remote serial device.
UseFixedBaudRate DWORD 0,1 0 "Use fixed baud rate" - If this flag is set, the value specified in "Bits per second" is used instead of the baudrate set by serial communications application.
FixedBaudRate DWORD 110-115200 0 "Bits per second" - Fixed baudrate value in bits per second (applied, if "Use fixed baud rate" is set).
UseFixedLineControl DWORD 0,1 0 "Use fixed line control" - If this flag is set, the values specified in "Data bits", "Parity" and "Stop bits" are used instead of the values set by serial communications application.
FixedLineControlDataBits DWORD 5-8 0 "Data bits" - Fixed Databits value (applied, if "Use fixed line control" is set) [values from 5 to 8].
FixedLineControlParity DWORD 0,1,2,3,4 0 "Parity" - Fixed Parity value (applied, if "Use fixed line control" is set).
0 - No parity check occurs.
1 - Sets the parity bit so that the count of bits set is an odd number.
2 - Sets the parity bit so that the count of bits set is an even number.
3 - Leaves the parity bit set to 1.
4 - Leaves the parity bit set to 0.
FixedLineControlStopBits DWORD 0,1,2 0 "Stop bits" - Fixed Stop bits value (applied, if "Use fixed line control" is set).
0 - One stop bit is used.
1 - 1.5 stop bits are used.
2 - Two stop bits are used.
UseFixedFlowControl DWORD 0,1 0 "Use fixed flow control" - If this flag is set, the value specified in "Flow control" is used instead of the value set by serial communications application.
FixedFlowControl DWORD 0,1,2 0 "Flow control" - Fixed Stop bits value (applied, if "Use fixed flow control" is set).
0 - Hardware flow control is used for the handshake.
1 - The XON/XOFF software flow control is used. The XOFF control is sent to stop the transmission of data. The XON control is sent to resume the transmission.
2 - No control is used for the handshake.
Local: HKCU\Software\FabulaTech\Serial Port for Remote Desktop\Server\PortSvcSettings\[xxx]\
LastMappedDstVirtPortNum DWORD 1-256 -1 Virtual port number which was last used for mapping physical port [xxx]. Used for stable mapping.
RealSpeedEnabled DWORD 0,1 1 Enable bitrate emulation.