If you are content with listening to the voice radio transmissions, and viewing the Talkgroup ID's as decoded on the PRO96's readout, you can stop reading here. If you want to take your monitoring of this radio system to a new level, READ ON.
The control channels which govern the operation of Westmoreland's APCO 25 digital system transmit a constant data steam which is used to maintain contact with all units at all times, and to control the functioning of the system. This stream communicates with all base, mobile and portable units, noting among other things their location and which talkgroups they are monitoring. A constant log of the units which are in range of one of the system's communications towers is maintained and transmitted in a data stream on the control channels. If you listen to a control channel, you will hear a rushing, white noise type of sound; it is this data stream which can be decoded to reveal interesting information about the system's internal operation.
The type of software which decodes the control channels is known as "Pro96Com" and is available at www.mvpcollaborative.com/p96. You will need to select the latest "zip" file containing the most uptodate "build" or version of the software, then unzip it and install it on your PC. This software installs on any Windows based computer, and is updated regularly with new "builds".
To enter the intriguing world of control channel monitoring, you need the PRO96 scanner and the interface cable described elsewhere on our Programming Software page. You will then need to download and install the Pro96Com software. To use the program, you will need to key in the following sequence ON THE SCANNERS KEYPAD: "PGM" "FUNC" "PGM" "PGM" . This places the Pro-96 into the "PC/IF Port Remote Access" mode, and allows the radio to communicate the control channel raw data stream via the cable to your computer. Then click on the "Data Read From PRO-96" button on the bottom of the PRO96COM software main page and the computer should begin receiving and decoding the control data.
All operational details of the software are covered in a comprehensive manual available free online in PDF format. You can download it from www.mvpcollaborative.com/p96/pro96com.pdf. THIS IS A MUST READ. It contains complete operational and troubleshooting information on this excellent piece of software, including screenshots showing what the various data screens on the software mean.
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