SIMSIII Receiver needs to run in Administrator Mode

Select the XML Receiver in SIMSIII Receiver Server (SRSIII)

Type in the Alarm.Com IP address and the port
Click on the XML Configuration button and select Http

Once the configuration is complete, Click OK to save.
Signals should start coming in right away.
If signals do not come in, check to see if the firewall is enabled. You may need to make an exception for SIMSRCV3.EXE.