ISY99 / ISY994 has an add-on 'Network Module' available for purchase directly from Universal (software download).  This module has the ability to send commands to network devices including the Global Cache iTach line of devices, providing a great way to send IR codes to a wired (IP2IR) or WIFI (WF2IR) module to control AV equipment, blinds, etc.

This is a quick point form guide.

iLearn  (free windows software)
Download the iLearn utility from the Global Cache site.
Run the iLearn utility.
Select “iTach Learner” from the drop down list under “IR Learner”
Enter the IP Address of the WF2IR.
Click the Connect Button
If successful, a Disconnect Button will replace the Connect Button.
Under Capture Options, set the Connector to 3 for the IR Blaster.
Leave all other Capture Options to their default values.
Hold the remote 1/4" from the hole on the back of the WF2IR
Press the button you want to capture, just once.
In about a second the code should appear in the Edit View window.
If it does not, press the remote button again, until it does.
Once it does, Enter something in the Button Name box.
Press the Trim Button, to eliminate extra code.
Now you'll see a "Send IR" button which you can use to test the capture.
Leave the Save format to "GlobalCache".
Press the "Save Data" button and the code appears in the Results menu.
Press "New File" to save the code into a new text file to cut/paste later.
Note: the code you saved does not yet have the CR/LF.

Create the Network Resource:
Log into the ISY and select the Networking Module.
You only have to work with the Network Resources Tab.
Select "ADD" and enter something in the name field (like TV ON).
Click on the field to the right where the "n/a" shows up.
This opens the Resource Editor.
Change Protocol from http to TCP using the drop down.
You will get a warnng message, if the Host field is empty. Click ok..
Enter the IP of the WF2IR in the Host Box
Change the port to 4998.
Change Mode to C-Escaped.
From the text file saved above, copy the code string beginning with “sendir”
to the end.
Paste the string (using CTL-V, Right mouse click does not work) into the Body box.
Click on the end of the string and append: ,\r,\l
Click the Update Button. The code will now appear in the Actual box.
Click Save.
You can not test it by clicking on the "Test Button"
The code will be sent and a Resource Response window will open up, showing a completion or error code.
The Network Resource is now available to ISY programs, under Action, to be used in ISY Programs.