MOTOTRBO Direct/Talk-Around

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trumpetman12
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Joined: Fri Aug 06, 2010 6:10 pm

MOTOTRBO Direct/Talk-Around

Post by trumpetman12 »

I've read that if you have a digital repeater pair programmed into your radio, if you go to talk-around/direct mode, the other radios will still unmute for the traffic.

My question pertains to the timeslot recognition. Does the radio broadcast timeslot data in the data stream? For instance, If channel 1 is TS1 and channel 2 TS2 (both repeated), if I am listening on ch. 2, will I still be able to hear someone if they go direct on ch. 1? I know there's no way to sync timeslots on simplex and only one conversation is allowed, but I don't know how it will react. It's either that, or does the traffic unmute regardless of the timeslot, as long as the color code matches.

Clear as mud huh? Thanks for any replies!
DPL
Posts: 185
Joined: Wed Jul 31, 2002 5:48 am

Re: MOTOTRBO Direct/Talk-Around

Post by DPL »

I don't know the protocol details, but I do know that the timeslot selection is irrelevant for simplex/talkaround. If I have radio A parked on timeslot 1, and radio B on timeslot 2, they both talk to each other in simplex mode as long as color code and talkgroup are correct.
trumpetman12
Posts: 71
Joined: Fri Aug 06, 2010 6:10 pm

Re: MOTOTRBO Direct/Talk-Around

Post by trumpetman12 »

Awesome, just want I wanted to hear. Thanks!
gopher
Posts: 169
Joined: Fri Dec 22, 2006 11:38 am

Re: MOTOTRBO Direct/Talk-Around

Post by gopher »

etsi spec says..
In direct mode, (talkaround )the transmitting MS (mobile station) shall establish the timing reference. Any MS wishing to send RC (reverse channel) signalling back to
the source shall synchronize to the forward path and shall base their RC timing on the forward path timing. Once the
source MS stops transmitting, any other MS wishing to transmit shall begin sending information asynchronously and
establish a new and independent time reference.
how its implement is another question
com501
Posts: 1088
Joined: Fri Nov 02, 2001 4:00 pm
What radios do you own?: Over 50 - All Motorola

Re: MOTOTRBO Direct/Talk-Around

Post by com501 »

In simplex, as long as the DCC match, the timeslot is irrelevant.
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borisf
Posts: 52
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Re: MOTOTRBO Direct/Talk-Around

Post by borisf »

So what is the preferred way of programming a dedicated simplex channel?
Will the radio operate in simplex mode automatically if TX/RX frequencies are the same?
Or do I have to set a bogus pair, check "Allow Talkaround" and turn on Talkaround via a side button every time this channel is selected?

Thanks.
com501
Posts: 1088
Joined: Fri Nov 02, 2001 4:00 pm
What radios do you own?: Over 50 - All Motorola

Re: MOTOTRBO Direct/Talk-Around

Post by com501 »

A MotoTrbo radio with US firmware will function in digital in a simplex mode simply by entering a simplex frequency.

You MUST assign a digital talk group, just as you would in a repeater scenario. This could be as simple as using the default '1' ID for your TX talkgroup.

As long as the color codes match the two radios, you can talk simplex.
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borisf
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Re: MOTOTRBO Direct/Talk-Around

Post by borisf »

So the talk group value is actually ignored/irrelevant in simplex operation as long as CCs match, but has to be set anyways because that field cannot be empty?
com501
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Joined: Fri Nov 02, 2001 4:00 pm
What radios do you own?: Over 50 - All Motorola

Re: MOTOTRBO Direct/Talk-Around

Post by com501 »

You really need to download the system planner. BOTH radios must have a CONTACT name (which is the actual CPS name for the field) and the TG assigned to the contact name must match between radios.
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borisf
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Re: MOTOTRBO Direct/Talk-Around

Post by borisf »

Got it, thanks.
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