DSD+ S1 S2 Question

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Ok, I understand that 1 on DSD+ during a decode is LCN1.....and so on and so forth. However what does the S1 and S2 signify? Are they data channels? Can they also be used for voice? I don't remember ever reading anything on the "S1 and S2"......
 

mtindor

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Ok, I understand that 1 on DSD+ during a decode is LCN1.....and so on and so forth. However what does the S1 and S2 signify? Are they data channels? Can they also be used for voice? I don't remember ever reading anything on the "S1 and S2"......
That's not quite true. Although a DMR control channel is _usually_ LCN 1, it doesn't have to be. So do not be fooled into thinking that just because you are sitting on a control channel, that it is automatically LCN 1. If you are using DSDPlus and monitoring a control channel, it will display what LCN it is.

Each DMR transmitter has two timeslots. Those timeslots can be used for voice / data / control in any combination.

On a CON+ system, if you sit on the active CC, then usually Slot 1 is the control channel data and Slot 2 is free for voice/data. I'm not sure if that is etched in stone though. I suppose the control channel data could be on Slot 2 if they want it to be, but I'm not positive about that.

S1 / S2 = Slot 1 and Slot 2

On a trunked voice channel, or a "conventional" DMR repeater, Slot1 and Slot2 can be used for data (messaging, GPS, etc) or can be used for voice.

On a trunked control channel (at least a CON+ control channel) one slot is always used for control channel data, and then the other slot is used for voice/data.

S1/S2 is always relative to the frequency/LCN pair that you are on. If you are on 123.1234 LCN one and DSDPlus shows S1/S2, that S1/S2 are specific to that frequency/LCN. If you tune to 456.4567 LCN 2 and you see S1/S2, that S1/S2 is specific to that frequency/LCN pair.

Mike
 
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Thanks Mike! That makes sense but what I see on my DSD+ is like:
S1
S2
1
2
3
4
With most of the voice traffic and control data going over the "1,2,3,and4" regularly. Is the S1 and S2 a simultaneous display of the time slots for that frequency that is active? Or maybe I have something wrong in the set up with the freq file as it has never displayed the frequency in the channel window. Either way I'll keep tinkering........

Thanks Again
 

mtindor

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Thanks Mike! That makes sense but what I see on my DSD+ is like:
S1
S2
1
2
3
4
With most of the voice traffic and control data going over the "1,2,3,and4" regularly. Is the S1 and S2 a simultaneous display of the time slots for that frequency that is active? Or maybe I have something wrong in the set up with the freq file as it has never displayed the frequency in the channel window. Either way I'll keep tinkering........

Thanks Again
Yes, you have it right.

1, 2, 3, 4 are the LCNs (frequencies)

S1 / S2 are the active timeslots on the _current_ frequency being monitored by DSD+ -- which isn't necessarily the "currently active" LCN.

For instance, if you have one receiver fed into DSDPLUs and you are sitting on the control channel, the S1/S2 are ONLY showing you informatoin about what is occurring on the two timeslots on the control channel frequency.

The 1, 2, 3, 4, etc let you know that there are active voice transmissions occurring on other LCNs (frequencies), even if you may not know what the actual frequency associated with that LCN is.

The S1/S2 won't show active on the graphic display of DSDPLus if it's just data. They will only show activity if there a talkgroup is active or if a private call is occurring between two radios.

The 1, 2, 3, 4, will show activity when there are voice calls on one of the LCNs / frequencies in the system.

And remember what I said before about a DMR control channel not always being LCN 1. If you sit on a control channel and wait for voice traffic to occur on the timeslot that isn't in use for control data, then DSD+ will reveal the LCN of the control channel. It's almost always LCN 1 -- but that's only because system maintainers typically use that default. The system maintainers could easily set the LCNs for each frequency to any valid LCN number they want, and throw us all off.

Mike
 
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