Toggling the Status Bit

Motorola talkgroup ID’s are sent as a 16-bit binary number. Normally, the last 4 positions in the number are 0’s, which result in all talkgroups being equally divisible by 16. These last four bits, however, can be used by the trunking system to indicate various status conditions. For example, an emergency status could be indicated by setting the second-from last digit to

1.Talkgroup 33264, then would be sent on the system as 33266 when the radio triggered its emergency status. By default, the BC796D ignores the last four digits of every talkgroup, effectively rounding them down to the nearest multiple of 16 regardless of the status bits.

2:SCAN OPTION 2:TRUNK → Select the bank → 0:STATUS BIT

1:ON

Talkgroups are rounded down to the next multiple of 16.

2:OFF

Talkgroups are not rounded down, so you can determine the value of the status bits.

Toggling End Code Detect

At the end of each transmission, a digital burst is sent so that radios on the system will quickly switch back to the control channel. Your scanner also listens for this code.

2:SCAN OPTION 2:TRUNK → Select the bank → :END CODE

1:DETECT

The scanner detects the end code and immediately switches back to the control channel.

2:IGNORE

The scanner waits for the carrier to drop before switching back to the control channel.

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Motorola APCO25, BC796D manual Toggling the Status Bit, Toggling End Code Detect