Batboard

I have an 800Mhz ASIII that is programmed to listen to a local 3600 baud, Astro digital trunked, simul-cast system. While listening to this system I see on the display unit id's that look like 707476.
I have noticed that the consoles on this system all begin with 70 and units vary from starting with 74 to 77.
My question is, what do the first two numbers mean? I know the individual id's can only go up to 65534 so there has to be something else that is being displayed with the unit id.

ASIII Stats.
Model: H04UCH9PW7AN
Flash: 599108-5F4600-1
Host: R07.13.00
DSP: N08.02.08
EMC: R03.29 DES-OFB / DES-XL

Astro System Stats.
800 Mhz
Sysid: 6F1E
CT: 76.60

All individual unit ID's on a Motorola trunked system begin with a '7'. All talkgroups begin with '80'. So the highest individual ID you'll see is '765534', and the highest talkgroup will be '804095'.

Tod

Thanks Tod, makes sense now...

Just to clarify a bit: the radios are programmed with User ID and T/G ID in hexadecimal. For display (and certain other functions), the hex value is converted to decimal and then added to either 700000 or 800000 for manipulation.

One system I am familiar with uses a variation on this approach for User IDs. Each officer is issued a portable radio, and the ID in that radio is his RTC (badge) number, plus 40000. For instance, Trooper 1553's portabel ID is 40000 + 1553 or 41553. This is then translated into its hex value (A251h) and programmed in the radio. When he transmits, it shows up on the screen as 741553, and the operator knows who it is.

The same thing is done for cruisers, but the number used is the fender number, and the adder is 50000. So Cruiser 269 is 50000+269 = 50269 = C45Dh = "750269."

Thank you all for the explanation on this. I see now that it is similar to how EDACS functions, of which I am very familiar with technically.
One other question though. Why when listening to a non Astro (analog)
type II system does the unid id not get displayed.

You can always refer to the talkgroup conversion information on radioreference.com at:

http://www.radioreference.com/modules.p ... page&pid=1

This will show you how to convert Decimal ID and HEX ID's to 70000 series IDs.

Hope this helps!