What exactly is the SRC and when should I consider using it?
The Smart Reader Client (SRC) is a software application that is deployed directly to the reader (for those readers that support an embedded application) or to a Micro PC / NUC / Raspberry Pi 'appliance' that manages the reader at the source. This puts intelligence directly at the reader source so it can run autonomously managing the reader's operation as well as communicating read events to its TagNet Server host. The SRC provides critical 'Store and Forward' capability when network connectivity is spotty and continually retries to send cached data until network connectivity is restored so read events are never lost. In simple terms it acts is an 'Event Broker' that follows the edge computing paradigm. The SRC is deployed under the following scenarios:
When a synchronous network connection (initiated from the TagNet Server) is not feasible to manage the reader directly via a LAN or WAN connection due to a poor QoS (Quality of Service). What is a poor QoS? Anything over 100ms latency point-to-point combined with excessive packet loss and/or network jitter can be problematic to keep all the message sets in proper sequence (under 50ms is recommended for a stable LAN/WAN connection). A typical example is when the reader is in a remote location (e.g. plant, warehouse, yard, or even within in a semi-trailer/container).
When the deployed readers are operating behind a firewall (outside that of TagNet Customer's domain) and the site security policy does not allow 3rd party devices on their network purely to access the Internet. In this case the Readers are managed by the SRC (deployed to a NUC) that utilizes a 4G/LTE modem router to reach the Internet and access the TagNet Server instance. This model can also be used when the readers are in a public location.
Note that the Customer needs to configure their network to support these WWAN devices coming in to the TagNet Server. Cell signal strength at reader location must be strong enough to enable data (as opposed to voice only) communications and 4G/LTE is recommended.
When the deployed readers are behind a firewall (outside that of TagNet Customer's domain) that prevents or restricts inbound traffic from the Internet. Instead of tunneling into the End-Customer's network by means of multiple public IP addresses, the SRC initiates all outbound traffic thus reducing many (if not all) firewall setup considerations. A typical example is when deploying readers in a VMI (Vendor Managed Inventory) scenario as shown below:
What are the downsides when deploying the SRC? If using very short read event cycles and doing directional intelligence, the SRC is not a good option as it simply cannot communicate quick enough with the server to change its inventory state before seeing the next read zone (if they are close together). The SRC does not support all features when reader is under direct Server control (e.g. RSSI filtering) however that gap is shrinking.
Installing the SRC
As of SRC v1.9 & Updater v1.3 (bundle v220.127.116.11) setup is entirely server based and there is no longer a requirement to connect to the client device (e.g. NUC, Pi, etc.) to configure/update local config files or services. Key features are a SRC listener that will shutdown the java.exe releasing the reader as well supporting multiple readers within the same SRC client install.
The SRC Agent's role is to monitor the health of the SRC and update the installed version based on the Smart Reader Installer Release Settings. This is done via a scheduled task (Win) that will check the version on a daily basis and upgrade if necessary. The Agent will also recover the SRC if it crashes via Process Management (Win). Additionally, when a new core instance is linked to an SRC profile, then the Agent will create a new instance sub-folder. Note that support for Linux SystemD Services is forthcoming for the Agent.
❖Quality of service (QoS) refers to any technology that manages data traffic to reduce packet loss, latency and jitter on the network. QoS controls and manages network resources by setting priorities for specific types of data on the network.
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