Chapter 15 Unified Threat Management for FortiOS 5.0 : Intrusion protection : IPS concepts : Signature-based defense : IPS sensors
  
IPS sensors
The IPS engine does not examine network traffic for all signatures, however. You must first create an IPS sensor and specify which signatures are included. Add signatures to sensors individually using signature entries, or in groups using IPS filters.
To view the IPS sensors, go to Security Profiles > Intrusion Protection > IPS Sensor.