They are on the Project SAFE-T system using the Hendricks County talkgroups.
Indiana Project Hoosier SAFE-T Trunking System Profile
www.radioreference.com
All law enforcement and fire/rescue agencies in Hendricks County use the same talkgroups on SAFE-T. All law enforcement and fire/rescue agencies in the county are dispatched by
Hendricks County Communications which is physically located in Plainfield.
Also, look at the Hendricks County listing in the database as some agencies still use their old VHF/UHF analog frequencies for comms that don't go through Hendricks Communications.
Scanner Frequencies and Radio Frequency Reference for Hendricks County, Indiana (IN)
www.radioreference.com