Handshake Process
Handshake process is for Neuron and IIoT platform to send a series of messages back and forth that make the data transmission to complete safely. A typical client-server communication would be the base of the handshake process. Neuron would act as server-side while IIoT platform will perform client-side to initiate the communication. But there are some special cases that would be discussed as below.
Typical handshake
A typical handshake process is just a client-server communication process. That is the client side (IIoT platform or web browsers) initiate the communication by sending the request message to server side (Neuron) who will send back the response after finishing the work as request. The following functions use typical handshake for data exchange with IIoT platform or web browsers.
Write Registers
Mode Change
Script Editing
User Administration
Registration
Registration is the only handshake process that the role of client-server has swapped. It is the Neuron to initiate the communication by repeatedly sending the registration request to IIoT platform until receiving the response message. If IIoT pass the registration, Neuron begin to transmit Heartbeat to IIoT platform. Registration process only happen in communication with IIoT platform.
Configuration
Configuration process involve two consecutive communication functions. First, IIoT platform or web browsers initiate a save configuration function 21 request to Neuron who will checkup the configuration in the request. If pass the checkup, it would save the configuration in the local buffer temporary and send back success response to IIoT platform or web browsers. Then, the second function 40 restarting with new configuration will be sent to Neuron who perform new configuration restart.
Clustering
By taking advantages of this mode change, a group of Neuron can provide clustering service. If hardware failure happens, IIoT platform can reinitialize by sending function 21 and function 40 to the extra inactive or standby Neuron to take over the work immediately. So, Clustering process is to implement the Configuration process when the hardware failure occurs.
Historical Trend Data
A running Neuron would generate trend data stream that may be stored in local device according to configuration setting. These stored trend data could be read by IIoT platform or web browsers through the historical trend function 82. Perhaps, there will be huge number of data to be transmitted. Therefore, we need to truncate the whole data set into several request / response message to complete the whole data set transmission. A token will be used to synchronize the data set in sequence. Initially, the token will be set to -1 at the IIoT platform or web browsers. Neuron would return a positive number token which means the data transmission is not yet completed. This token will be coped to next request message. This mechanism will be repeated until the response token is -1.
Historical Alarm Log
As same as Historical Trend function, a running Neuron would generate a lot of alarm message that will be stored in local device according to alarm category settings. These stored alarm message could be retrieved by IIoT platform or web browsers through the historical alarm function 81. Because of same reason as Historical Trend function, a token mechanism will be employed during the consecutive message transmission.
Login
Both IIoT platform and web browsers are required to login Neuron at the beginning. By default, IIoT platform would login with high privilege automatically when the connection has made. After the login pass, Neuron then start the transmission of heartbeat and telemetry.