SDS200 ID Search /ID Scan Question

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TailGator911

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I'm sure it's already been covered here, but I choose the path of least resistance. When scanning a Favorite List, does either/or ID Search and/or ID Scan have any discernible affect on scanning speed?
 

GTR8000

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What type of system? How many sites are you scanning?

The general answer is no, it has no bearing on scan speed. In fact, when you scan a trunked system that uses a dedicated control channel (e.g. P25, Motorola 3600, MOTOTRBO Connect Plus, etc.) there really is no such animal as "scan speed". The scanner dwells on the control channel waiting for voice call grants, then switches to the corresponding frequency to receive them. When complete, it switches back to the control channel and dwells until the next grant.

You can program 1 or 100 talkgroups, ID Scan or ID Search, and it's all the same. The scanner is processing the TGID's it sees in the control channel stream, it is not continuously scanning through a bunch of talkgroups hoping to find one that is active.

Of course scan speed can be affected based on the number of systems and sites being scanned. If you scan 2 or more sites, even of the same system, then it will take the scanner 2 or so seconds to jump between sites, assuming you don't tweak anything like the hold time settings per-site.
 

TailGator911

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Yes, I know scan speed can be affected by the number of sites you are accessing, but wondered about any noticeable differences when scanning one single (normal size) Favorite List, one system, etc. Thanks for the quick reply!
 

letarotor

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I'm not sure if it's in the manual but the information used to be in the old manuals for scanners on just how fast the scan speed was and how fast the search speed was too. Get a PDF copy of the manual and do a search for "scan speed" and I bet it will find the answer if it's in there.

But in the same vein, I would have to say ID scanning would likely be faster if you were in the ID scan mode since the ID search mode is searching for any and every transmission on the TRS and not just the TGIDs you've programmed into the radio to scan.

I obviously don't know if I'm answering your question. But there should be some information on both the ID scan and ID search speeds in the manual still I would think.

Brian (COMMSCAN)
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TailGator911

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Thanks, Brian! It just seems like good sense that adding 'Search ID' to the mix when you are already scanning would hamper the speed with simultaneous tasks being performed. But, as GTR8000 just reminded me, there is a lot to take into consideration whenever a simple question is asked about a digital P25 system or some variant. Things ain't so easy these days :)
 

Ubbe

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At the beginning of SDS100 it scanned up to 100ch/s and maybe more but could be slower depending of how large frequency jumps where neccesary. It was some problems with that high scan rate and now it is fixed at 45ch/s for the SDS100. It's probably the same for SDS200.
There's no difference between search and scan of frequencies and sorting frequencies in order doesn't do anything for the scan rate, except jumps to and from the VHF-LOW band.

When scanning digital frequencies and frequencies with subtones and if there's a carrirer on that frequency, then it has to stop scan and evaluate what kind of signal it is and if it matches the programming that have been done to that frequency in the scanner. On a trunked control channel it takes up to 1,5 sec to sync and decode the data to be able to tell if a TG are in use. The SDS100 searches thru thousands of TG's in one second and it doesn't matter if you do ID search or ID scan as it has to find all TG's you have avoided or programmed with name tags and so on. So no mode will scan TG's quicker than the other compared to that initial 1,5 sec that it has to stay on the frequency.

To increase the scan speed of digital systems you will have to reduce the amount of sites in the scan cycle.

/Ubbe
 

ofd8001

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But in the same vein, I would have to say ID scanning would likely be faster if you were in the ID scan mode since the ID search mode is searching for any and every transmission on the TRS and not just the TGIDs you've programmed into the radio to scan.
That's not completely accurate. Trunked system monitoring is different than conventional system monitoring. In trunked systems, the scanner does NOT go one talkgroup to another talkgroup to another, etc. Rather, as mentioned above, it "looks" at the control channel for channel grants - assignments of talkgroups to voice channels.

ID Scan is a "positive" situation. In this, the scanner is looking to see if the channel grants match your list of desired talkgroup groups. If the granted communication is for a talkgroup in your list, the scanner will go to and monitor the assigned voice channel. In other words, "listens" to only those talkgroups you tell it to.

ID Search is a "negative" situation. In this, the scanner gets the channel grant, looks to see if you have declined to listen to a talkgroup. This would be a locked out/avoided talkgroup, If the talkgroup is not on the denied list, the scanner will go to and monitor the assigned voice channel. In other words, "listens" to every talkgroup it comes across, unless you have told it not to.

There is no scan speed difference. If there is an inactive/no on-going transmissions on a trunked system, it talks 1-2 seconds per site to "listen" to the system. This can be verified by trying it.
 
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