Motorola Talkgroups

Type II Talkgroup Conversions

Marshall Sherard, KE4ZNR, has a talkgroup converter that can be used to convert between the various formats of talkgroups.

Talkgroups can also be converted between the various formats by using the Microsoft Windows scientific calculator. It provides a Decimal to Hex function that works very well.

Note that all Motorola Type II talkgroups are evenly divisible by 16.

Type II talkgroup IDs come in three flavors:

• Uniden Trunktracker format, e.g. 41072 ("U" in examples below, Range: 0 - 65504)
• Motorola 3 digit hexadecimal, e.g. A07 ("M3", 000 - FFE)
• Motorola 6 digit decimal, e.g. 802567 ("M6", 800000 - 804094)

Conversion Formulae

The notation Dec_to_Hex(X) means convert X to its Hex equivalent using MS-Windows calculator or similar. The notation Hex_to_Dec(X) means convert X to its Decimal equivalent by the same means.

• M6 to U: (M6 - 800000)*16 = U
• M6 to M3: Dec_to_Hex(M6 - 800000) = M3
• M3 to U: Hex_to_Dec(M3)*16 = U
• M3 to M6: Hex_to_Dec(M3) + 800000 = M6
• U to M3: Dec_to_Hex(U/16) = M3
• U to M6: U/16 + 800000 = M6

Examples:

• Convert the M6 format ID, 802617 to U format:

(802617 - 800000)*16 = 41872

• Convert the M6 format ID, 802617 to M3 format:

Dec_to_Hex(802617 - 800000) => Dec_to_Hex(2617) = A39

• Convert the M3 format ID, A39 to U format:

Hex_to_Dec(A39)*16 => 2617*16 = 41872

• Convert the M3 format ID, A39 to M6 format:

Hex_to_Dec(A39) + 800000 => 2617 + 800000 = 802617

• Convert the U format ID, 41872 to M3 format:

Dec_to_Hex(41872/16) => Dec_to_Hex(2617) = A39

• Convert the U format ID, 41872 to M6 format:

41872/16 + 800000 = 802617

APCO-25 Talkgroup Conversions

To avoid confusion, it should be noted that APCO-25 system talkgroup IDs are also displayed in multiple formats: decimal (e.g., "26570") and hexadecimal (e.g., "675c"). To convert between the two formats, simply perform a straight hex-to-decimal conversion (or decimal-to-hex conversion), again using the Windows scientific calculator or one of the many free conversion calculators available on the Internet.

Type II Special Status Bits

Type II systems use these status bits for special transmissions such as Emergency, Patches, DES/DVP scrambled transmissions, and Multiselects on Motorola Trunking systems. Motorola Trunking radios directly interpret them for their special functions, thus no difference is noticed by the person with the radio. The Trunktracker scanners however interpret these special talkgroup status bits as different talkgroups entirely. Below is the conversion chart for these special status bits.

Therefore, if a user was transmitting a multi-select call on talkgroup 1808, the trunktracker would actually receive those transmissions on 1815. Some common uses of these status bits are as follows: When a user hits their emergency button, all conversations on the talkgroup revert to the Emergency status talkgroup (ID+2) until the dispatch clears the emergency status. Therefore, if someone hit their emergency button and their radio was on talkgroup 16, all communications would switch to talkgroup 18. A lot of Fire and EMS departments dispatch tone-outs and alarms as Multi-select communications (ID+7). Therefore, if your fire department dispatch talkgroup is 1616, and they do dispatch tone-outs and alarms as Multi-selects, then those communications will be on talkgroup 1623.

TTID + #	Usage
ID+0	Normal Talkgroup
ID+1	All Talkgroup
ID+2	Emergency
ID+3	talkgroup patch to another
ID+4	Emergency Patch
ID+5	Emergency multi-group
ID+6	Not assigned
ID+7	Multi-select (initiated by dispatcher)
ID+8	DES Encryption talkgroup
ID+9	DES All Talkgroup
ID+10	DES Emergency
ID+11	DES Talkgroup patch
ID+12	DES Emergency Patch
ID+13	DES Emergency multi-group
ID+14	Not assigned
ID+15	Multi-select DES TG