There is a control protocol document available here: http://dataprobe.com/support/manuals/ctl/dxp_proto_v100218e.pdf
There is also a utility we have that will translate the batch file command line parameters to the DxP protocol and control the relays. (and therefore your gate)
The program and sample batch file is on the resource page for the ipio8 under C Examples.zip.
Or you can directly download from here is you prefer... http://dataprobe.com/files/control/dxp_1.2.zip