# Tag Persistence and Scan Modes

#### Tag States A and B

During a scan, RFID tags transition between two primary states:

****State A (Not Charged):****<span style="white-space: pre-wrap;"> The tag is at rest and ready to be read.</span>

****State B (Charged):****<span style="white-space: pre-wrap;"> The tag has been energized and read by the scanner.</span>

<span style="white-space: pre-wrap;">Once a tag is scanned and enters </span>****State B****<span style="white-space: pre-wrap;">, it must fully discharge and return to </span>****State A****<span style="white-space: pre-wrap;"> before it can be accurately registered in a new, distinct scanning session. The time required for this transition is known as the persistence or "cooldown" period.</span>

#### Selecting the Appropriate Scan Mode

<span style="white-space: pre-wrap;">To manage this charging cycle effectively, your system provides two scanning modes: </span>****Speed****<span style="white-space: pre-wrap;"> and </span>****Density****.

##### ****Speed****<span style="white-space: pre-wrap;"> Mode</span>

The mode is designed for rapid, continuous scanning operations.

****Functionality:****<span style="white-space: pre-wrap;"> The scanner charges tags for a minimal, unnoticeable duration.</span>

****Benefit:****<span style="white-space: pre-wrap;"> Because the charge is brief, tags discharge almost instantly, eliminating the cooldown period. This allows you to conduct back-to-back scan sessions without delay.</span>

****Recommended Use:****<span style="white-space: pre-wrap;"> Ideal for standard daily operations where wait times are undesirable, such as quick spot-checks or rapid order processing.</span>

##### ****Density****<span style="white-space: pre-wrap;"> Mode</span>

The mode is designed for thoroughness and high-volume scanning in crowded environments.

****Functionality:****<span style="white-space: pre-wrap;"> The scanner applies a longer charge to the tags to capture a higher volume of data within a single session.</span>

****Benefit:****<span style="white-space: pre-wrap;"> Maximizes the number of tags read, ensuring comprehensive capture even in dense or tightly packed areas.</span>

****Requirement:****<span style="white-space: pre-wrap;"> Because the tags receive a longer charge, they require approximately 5 minutes to discharge and return to State A. Initiating a new scan before this cooldown completes may result in unread tags.</span>

****Recommended Use:**** <span style="white-space: pre-wrap;">Best suited for comprehensive audits, cycle counts, or scanning densely packed pallets. It can also be used effectively as a control scan when performing an </span>[Audit](https://kb.simplerfid.com/books/auditing). You must plan for the 5-minute wait time between scans in the same area.

#### Configuring Scan Settings

<span style="white-space: pre-wrap;">You can toggle between </span>[Speed and Density](https://kb.simplerfid.com/books/mobile-app/page/scan-settings)<span style="white-space: pre-wrap;"> modes directly within the application interface:</span>

[![image.png](https://kb.simplerfid.com/uploads/images/gallery/2026-05/scaled-1680-/CPUimage.png)](https://kb.simplerfid.com/uploads/images/gallery/2026-05/CPUimage.png)