FarSync X25 T4Ee

This top of the range FarSync X25 T4Ee PCIe card provides 4 high performance X.25 communications lines handling many different line signalling modes. A PCI version is also available.

FarSync X25 T4Ee 4 port X.25 communications card shadow


The FarSync X.25 T4Ee product is a high quality X.25 solution for business, government and military applications, it has been developed to provide high performance, versatile X.25 connectivity for Linux and Windows systems.

The PCIe card will support 4 X.25 lines at speeds to over 2.048 Mbits/s. The highly flexible universal network connector supports RS232, X.21, RS530, RS449 and V.35 network interfaces.

Line signalling modes: NRZ, Manchester encoding, FM0, FM1 and Conditioned Diphase are handled by the onboard FarSite customisable communications controller as well as soft selectable line termination resistance.

The product is supplied with a free 5 year warranty.

Product details

The FarSync X25 T4Ee 4 line card runs an AMD processor with SRAM and an embedded HDLC controller connected to the Server/PC through a PCIe bus.

Network Interfaces

The multi function line drivers available on all the ports support X.21 (V.11), V.35, RS232 (V.24, X.21bis), RS530 (EIA530, RS422) and RS449 network interfaces, all soft configurable and ESD protected from static charges.

X.25 line speeds of over 2.048 MBits/s are supported.

Clock Generation

As well as external (line generated) clocking FarSync X25 T4Ee also supports card generated clocks with speeds from 9600 baud to over 10 Mbits/s, each line can be set to a different speed.

Line Signalling Modes

A wide variety of line signalling modes can be handled including NRZ plus the self clocking (clock for the data is decoded from the incoming data line) line signalling modes NRZI, Manchester Encoding, Conditioned Diphase (also known as Differential Manchester), FM0 and FM1 at speeds of up to 10 MBits/s. This means separate clock lines are not required, these line signalling modes, are a soft configurable alternative to NRZ and a reliable way of handling long high speed cable runs. Some X.25 implementations particularly require Conditioned Diphase and this card can support those.

Line termination is supported on all the balanced pair signals for X.21 (V.11), V.35, RS530 (EIA530, RS422) and RS449 (RS422 signalling) operation. The line termination resistors may be soft selectable on a port by port basis. The addition of line termination resistors can be helpful in improving signal quality on long higher speed lines.

Multiple Cards

The drivers supplied with Windows and Linux allow large numbers of ports to be supported by the installation of multiple FarSync cards in a Server. Typically 12 or more cards (24+ ports) can be supported; the card limit is only dependent on the resources available in the host Server and the total bandwidth of the PCIe/PCI/PMC bus.

PCIe Compatibility

FarSync PCIe cards are suitable for systems with a PCIe bus, covering single and multi-processor systems. These cards are compliant with PCI Express Base specification revision 1.0a and above. The FarSync adapters are bus mastering, 1x (single lane) cards.

If you are not sure about your particular system, contact us and we can provide advice on the card that is most suitable for you.


This four port card uses a single large high density 100 pin HIPPI type connector, all four lines are available though this connector. The quad port cable HCR4 attaches to the card and splits out the four network interfaces into separate network connectors to provide support for EIA-530 (RS422) and RS232. X.21, V.35 and RS449 are available through transition connectors. Details of the cables and converters available are listed in the cables section of the Order Information table. Crossover cables, sometimes referred to as null modem cables, or DTE to DCE conversion cables are also available.

FarSync X25 T4E+ PCI card

The FarSync X25 T4E+ has a very similar set of features to the FarSync X25 T4Ee except it is for a PCI bus.

FarSync X25 T4E+ PCI X.25 adapter
FarSync X25 T4E+ a 4 port X.25 PCI adapter

Order Information

The X.25 software firmware, drivers, utilities and the X.25 Developers Toolkit are all included with the FarSync adapter. Line cables are ordered separately.

The software and documentation is downloaded from this website using a code supplied with the FarSync X25 adapter, it includes:

  • Drivers for Linux and Windows.
  • Numerous example applications with source code
  • Documentation for all the APIs in Adobe PDF format
  • Source code for Linux drivers and API Libraries
  • Network monitor and various useful utility programs

New releases of the software with enhancements and fixes are made available for free download from the Download page in the Support section of this web site.