SDS 100 NAC Code

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Oct 7, 2020
"Negative Delay" forces the scanner to move on (resume scanning) if the conversation lasts over the set time. So, if you set the delay as a negative 10 seconds (-10), then after ten seconds the scanner will resume scanning regardless of whether the conversation it was monitoring is done or not. I use a negative delay on the automated dispatch channel for Dallas Fire Rescue. "Dispatch Debbie" has a habit of going ADHD, repeating the same traffic repeatedly (same address, call type, & units assigned).

With a zero delay, the minute the sheriff's channel breaks between conversations, the scanner will move to the next one it finds. (For example, a unit in the field calls the dispatcher, there likely will be a brief break until the dispatcher answers. So, you would be leaving in the middle, more or less, of a call on the sheriff's channel even if it were not finished.) Or, if the call on the other channel had started during the same time frame that you were hearing the sheriff's call, you're going to land in the middle of the one taking place on a different channel or talkgroup. If that other call then finishes quickly, the scanner will move on from there. If it is dropping out of the S.O. channel, while someone is still talking, and lands in the middle of something else, that suggests that it may be leaving the S.O. channel due to a priority setting.

As far as scan speed, remember that the scanner will take up to 1.5 seconds to acquire a control channel on a trunked system's site, then look for active talkgroups. If you have multiple sites on the same system programmed, you would be staying within that system longer. You'd have the same effect if you had multiple trunked systems. You should only have the sites (or systems) of interest, that are in range, set to be scanned. You can use location to have those that are out of range disabled.

Also remember that if you have the filter for one or more sites or departments set as "Auto", that will also drag down your scanning speed. When using auto, the scanner will try all the various filter settings to see which one is most effective. But it's not memorizing the the setting that was optimal. So, the next time it hits that same site or department, once again it tries every combination. If you have an agency where you need to use a specific setting (other than Normal, or off), include that setting in your programming so that you do not induce more delay.
Thanks Steve for the informative answer. I will check my settings and see how it works. Thanks again for the help. Harry
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