BECKHOFF:
Requires the installation of "TwinCAT TCP/IP Connection Server"
This requires the Library "TcpIp.Lib"
(Standard.lib; TcBase.Lib; TcSystem.Lib are then automatically included)
Programming environment:
NT4, W2K, XP, Xpe;
TwinCAT system version 2.8 or higher;
TwinCAT Installation Level: TwinCAT PLC or higher;
Target platform:
TwinCAT PLC runtime system version 2.8 or higher.
PC or CX (x86)
TwinCAT TCP/IP Connection Server v1.0.0.0 or higher;
NT4, W2K, XP, XPe, CE (image v1.75 or higher);
CX (ARM)
TwinCAT TCP/IP Connection Server v1.0.0.44 or higher;
CE (image V2.13 or later);
http://www.beckhoff.com/english/twincat/twincat_tcpip_server.htm