EDACS SCAT (Single Channel Autonomous Trunking) systems operate on a single channel and alternate control data with analog voice traffic. While some scanners that have this programming option cannot track ID’s in this system, it can eliminate the control data so that all you hear is the voice transmissions when you monitor this type of system. 
Also, this excerpt from The Repeater Builder's Technical Information Page (PDF File)
SCAT is a unique application of a GETC shelf that is
configured as an option to an EDACS Repeater. The SCAT
option allows a single repeater to alternately perform the
Control Channel or Working Channel functions. This extends
the trunked operation into difficult areas such as ravines,
tunnels, etc. and extremely low traffic density areas
such as shopping malls.
SCAT systems are available for all EDACS wideband
configurations: VHF, UHF, and 800 MHz.
The SCAT channel may be configured as stand-alone
system or as part of a multisite trunking network.
M/A-COM Website Datasheet on SCAT (PDF File)
Return to the EDACS page.