hi,
we are currently running two imagePro HD with a widget designer std and the syntax jan described above is absolutely correct. you can find all the commands in the users manual.
if you want to switch the inputs, for example, you have to use the TCPSend,'ID','Message' string in widget designer. ID is your tcp connection ID and the message for switching the inputs is "RTE" followed by a space followed by the inputnumber followed by a space followed by [CR].
the complete script for changing to input one is: TCPSend,1,RTE 1 [CR]
we found out that the imagePro HD doesn't always recognize the tcp signals in some cases so you have to send the command again.
it is also not possible to create a multiple count of connections to the imagePro because the port is blocked if one widget designer is connected. you may notice that if you want to run a backup widget designer or want to controle the same imagePro from different places.
have fun
useful hint: the image pro uses the port 10001!