Virtual Serial Port Driver (VSPD) turns serial ports of Tibbo Device Servers into remote COM ports of your PC. VSP Manager is used to create and manage Virtual Serial Ports (VSPs).

New VSPD introduces additional routing and connection modes, support for reverse connections, connection timeouts, and MAC->IP mapping.

Not sure what Virtual Serial Ports are for? Watch this presentation!

New features in Release3

Inband on-the-fly commands. It is now possible to pass on-the-fly commands inside the TCP data connection itself thus eliminating the need for sending them in a separate UDP stream.

New Routing Mode Property defines whether the VSP will work as a client (incoming connections only), server (outgoing connections only), or server/client (both).

New Connection Mode Property offers an option to make the VSP establish a data connection as soon as the VSP is opened by an application.

New Connection Timeout Parameter. You can now make the VSP abort an idle connection across which no data has been transferred for a predefined number of minutes.

New MAC-->IP Mapping feature. You can now reference the destination Device Server by its MAC-, not IP-address (which can change over time due to the use of DHCP).

Remote control of RTS/CTS/DTR/DSR lines. The status of these lines can now be exchanged between the VSP and the Device Server.

Inband on-the-fly commands

Previous versions of VSPD could only send on-the-fly commands as UDP datagrams to port 65535 of the Device Server. This works great for "local" Device Servers but may pose problems in WAN installations- routers and firewalls often ban UDP traffic so UDP on-the-fly commands may not be able to reach their destination. New inband on-the-fly commands are sent right inside the TCP data connection itself thus eliminating the need to use UDP traffic for command transmission.

See also:
Inband commands (Firmware)
Improved connectivity and speed (DS Manager)
On-the-fly commands (online manuals)

New Routing Mode Property

To achieve more "operational symmetry" between the Device Servers and the VSPD we have added the Routing Mode Property, similar to the Routing Mode (RM) Setting of the Device Servers. Three available options are client (incoming connections only), server (outgoing connections only), and server/client (both).

See also:
Routing Mode Property (online manuals)
Routing Mode (RM) Setting (online manuals)

New Connection Mode Property

It is now possible to select when the VSP will establish an outgoing data connection: when an application sends its first data (on data) or right after the VSP is opened (connect immediately). Connect immediately option is useful for establishing so-called "reverse" connections.

Reverse connections are used in "asymmetrical" networks in which only one side of the link (VSP in this case) can "see" the other side (Device Server). If it is the Device Server that is supposed to send the first data across the connection then the Device Server won't be able to do this because it cannot "see" the PC (VSP). By instructing the VSP to connect to the Device Server right from the beginning you make sure that by the time the Device Server has the data to send the data connection will already be available.

This Property is similar to the Connection Mode (CM) Setting of the Device Server.

See also:
Improved support for WAN installations (Connection Wizard)
Connection Mode Property (online manuals)
Connection Mode (CM) Setting (online manuals)

New Connection Timeout Parameter

The VSP can now be set to abort idle data links, i.e. links across which no data is transferred (in any direction) for a predefined number of minutes. This helps cancel abandoned and hanged links that may prevent other Device Servers from connecting to the VSP (and other VSPs from connecting to a particular Device Server).

This Property is similar to the Connection Timeout (CT) Setting of the Device Server.

Connection Timeout Parameter (online manuals)
Connection Timeout (CT) Setting (online manuals)

New MAC-->IP Mapping Feature

Since Tibbo Device Servers now support DHCP it is possible that the IP-address of the "target" Device Server will change over time. By referencing the target Device Server by its MAC-address the VSP makes sure that it will always be able to find this Device Server no matter what its IP-address will be in the future.

This feature works for local Device Servers only.

See also:
DHCP support (Firmware)
Single-destination mode (online manuals)

Remote control of RTS/CTS/DTR/DSR lines

Previous versions of VSPD did not handle RTS/CTS/DTR/DSR signals in any way. Now, the status of control signals can be exchanged with the Device Server.

In many systems, these signals are "manually" manipulated by the software application on the PC. For example, some systems use RTS line as a "data strobe"- a pulse is generated on the line each time the data is output by the PC. The VSP will now work correctly in such systems.

Additionally, a very precise synchronization is now achieved between the RTS/CTS/DTR/DSR line control and the data output by the VSP when on-the-fly commands are sent in the inband fashion (see above).

See also:
Remote control of RTS/CTS/DTR/DSR lines (Firmware)