Sequential Read Mode

Overview

Sequential Read Mode is one of the two foundational read modes in Keonn's readers. It works by managing the RFID module to control when and where read tags.

Best practices

Sequential Read Mode is meant to be used when polling the reader for data and as such, even when started, the reader waits for inventory operations to start reading.

These inventory operations are described in more detail in the REST API docs but they are:

  • /device/jsonMinLocation

  • /device/inventory

These two operations will trigger a sweep to read using all antennas. The reader will spend the configured time per antenna and will use the antennas configured.

Because of its synchronous nature, asynchronous integration services such as HTTP or MQTT may not behave as intended.

Here is a diagram on how the read mode works:

AdvanNet's monitor periodically issues inventory operations to retrieve data from the reader in order to show data. Keep it in mind when working in SEQUENTIAL as it will artificially issue inventory requests.

Antenna capabilites

Because in this read mode it is AdvanNet that manages directly the RFID module there are software restrictions on how many antennas a reader can use:

  • AdvanReader-m4-160: 1024 antennas*

  • AdvanReader-m2-160: 512 antennas*

  • AdvanReader-m4-160.02: 64 antennas

  • AdvanReader-m2.70: 32 antennas

  • AdvanReader-m1.70: 16 antennas

* While possible, the read times are large.

Alternative working modes

Due to the antenna limitation inherent to the AUTONOMOUS read mode, users that want to take advantage of the large amount of antennas a reader can handle while enabling an Asynchronous/Autonomous-like behaviour in the reader can activate the option Read automatically under Read Modes in AdvanNet. This read mode isn't truly autonomous because using fixed time per antenna can cause under/overshooting inventories.

Under Read modes -> Advanced settings -> Advanced JSON conf setting [{"autoReadCycleDelayMs": 60000}] will set up a delay between inventories. Pretty useful for setting periodic, if infrequent, automatic inventories.

Example of typical settings

If you wish to get continuous inventories please check this option and DO NOT browse the Monitor screen.

Summary of differences with AUTONOMOUS

This read mode by default works via inventory requests, the AUTONOMOUS is asyncronous: reading from 3177 or setting up the services is the way to work.

On this read mode there are no software limitations on how many antennas to use, AUTONOMOUS is limited in this regard.

This read mode allows, with creative use of the REST API, controlling what antenna to use and when. In AUTONOMOUS is the RFID module who controls what antenna to use.