AlphaMon Technologies
The AlphaMon Platform incorporates a number of embedded technologies to enhance and simplify connectivity thus ensuring your data is readily available and secure.
Fortunately, the AlphaMon Platform hides most of the technical complexities from the user making installation relatively simple; maybe not 100% child’s play – but hopefully, close to it. But if you’re one of those users needing to dig deeper for the purpose of integrating and interfacing, this section is for you.
Some of the supported communications technologies are single channel (also called point-to-point) such as USB Serial and Bluetooth Low Energy (BLE). However other supported communication technologies such as LoRa, MQTT and WiFi support multiple connections (point-to-multipoint).
Point-to-Multipoint communication channels allow simultaneous connections with multiple receivers. For example, you could have one AlphaMon Outdoor Module connected to and interrogating your inverter via Modbus. The data from the inverter is sent in real time via LoRa radio to any registered and connected AlphaMon Indoor Module. Thus you could have an Indoor Module for each room in the house or office each displaying the output from the single inverter.
Each of those AlphaMon Indoor Modules can also send commands back to the inverter via the LoRa connection and the AlphaMon Outdoor Module.
In yet another scenario, you could have multiple AlphaMon Outdoor Modules connected to multiple inverters ond/or Modbus-enabled energy meters, each sending their data to a single (or multiple) AlphaMon Indoor Module receiver/s.
Each communications channel has different properties as described below. Thus you can chose one or more communication channels to best meet your needs. All the channels operate concurrently except for WiFi and Bluetooth (BLE) which share a common antenna,, so only one of these can operate at a time.
The AlphaMon Platform also supports a number of additional technologies not directly related to communications including multiple Digital and ADC inputs, a 32 G.Byte memory storage card, load switching and a generator auto-start interface.
USB-C Serial
The USB-C Serial channel is available on both the AlphaMon Indoor and Outdoor Modules. It can be accessed via the USB-C socket on the right-hand side of the integrated ESP32 sub-board. The AlphaMon Module can also be powered via this port providing your USB power supply is rated at 2 Amps or more.
A brief summary of the characteristics of this communications channel is as follows:
- Default speed is 19200 bps, 8 bits, No Parity, 1 Stop bit.
- The log includes all start-up activity for fault finding and maintenance, including:
- Device’s unique MAC address
- OLED display settings
- The available WiFi Access Points detected during the scan
- The current WiFi connection
- All Modbus connections (inverters, energy meters, etc.)
- Global NTP time synchronisation activity
- An NTP time and date stamped log of each communication sent and received
- Best used during device setup and/or when analyzing data traffic
- Connecting and/or disconnecting a USB cable whilst the AlphaMon is operational may cause the AlphaMon to reboot.
- May be used to power the AlphaMon module from a USB power bank thus enabling mobile operation. Note: the AlphaMon Modules also include a built-in connector and charger for a Lithium battery (LiPo 3.7V, such as an 18650 cell) which also supports mobile operation.
- Powering the AlphaMon from a battery or a USB power supply which is not connected to your regular AC power supply will ensure it keeps operating, even if the grid power fails.
- Data from the USB-C port can be displayed and captured to a file using popular terminal emulation software such as Putty. (Putty runs on many operating systems including Windows, Linux, Apple iOS and Unix)
- Serial data transmitted via the USB-C port is structured in ways that facilitate automated parsing and data analysis.
- The small end of a USB-C cable can be fed through the cable gland on the base of the AlphaMon Outdoor Module and left in place to facilitate periodic connection to the Serial port. This can save time because the lid of the enclosure doesn’t have to be removed each time.
LoRa Radio
AlphaMon’s support for LoRa data transmissions allows you to connect two or more AlphaMon Modules without the time and expense of running new cables. It also provides a solution when your WiFi doesn’t have the range to connect the indoor and outdoor modules.
Bear in mind that LoRa technology is specifically designed for low data rate transmissions and, in some countries including the EU, the percentage of connected airtime is restricted which further restricts how much data can be transmitted.
To address the problem of low LoRa data rates the AlphaMon includes a scheduling system that ensure that high priority data such as voltage, power flows and grid activity are sent with high frequency. Less important and relatively static data such as the battery state of charge (SoC) is sent less frequently – say every 10 minutes. Even lower priority data is sent at extended intervals.
The key features of the AlphaMon LoRa channels are as follows. More information about spread-spectrum LoRa can be found on the Home page.
- Very low data rates and long rage transmissions (up to 15km line-of-sight, or more!)
- Point-to-multipoint data communication
- Highly compressed data packets, designed to reduce total connected air time
- Supports encrypted data transmissions
- Range of antennas available (1/4, 1/2 and full wave) for range optimisation
- Scheduled transmission intervals based on data priorities
- On-board LED blinks briefly for each LoRa data packet received
- Data logs include register addresses and values of transmitted and received packets
- Operates in the unlicensed Industrial, Scientific and Medical (ISM) radio band
- Allocated ISM spectrum frequency differs by country so be sure to order the correct AlphaMon Modules for your country to ensure your installation is legal.
WiFi
The AlphaMon Modules offer 2.4GHz WiFi connectivity (802.11 b/g/n, up to 150Mbps) to support the following functions:
- Initial configuration. Refer to the Installation Instructions for more information
- MQTT connectivity
The AlphaMon Module generates a temporary WiFi Access Point and web page/s to simplify configuration and setup. Enabling the Access Point requires the user to press a button on the AlphaMon Module to enhance physical security.
After configuration and boot-up the AlphaMon Module automatically disables MQTT data logging if a connected WiFi network and registered MQTT server can’t be found.
Note that the AlphaMon Platform doesn’t support hard-wired Ethernet connectivity to your local network’s router or switch.
MQTT Publish & Subscribe
The AlphaMon Platform supports automated publication to an MQTT server of your choice. MQTT servers are available in paid, free, hosted and self-hosted versions to suit your applications. Paid subscriptions are usually charged based on the amount of data sent and/or received.
The MQTT protocol supports an authenticated publish & subscribe messaging model, not unlike the POP3 protocol used for Internet email. Using this data model the AlphaMon Platform can optionally connect and publish structured data to your MQTT server of choice..
The data structures used by the AlphaMon Platform are designed to facilitate enterprise-grade data collection and analysis. Key data is published under multiple headings to facilitate the various user groups in your organisation, such as entity, department, user group. etc.
Authorised MQTT users can register on the server using their username and password and place requests for one or more MQTT data streams, depending on their level of authorisation.
In short, the MQTT server will retain the data until all registered users have collected their requested data streams or until the data has expired, as defined by the server’s administrator.
Modbus
Modbus, or more specifically Modbus-RTU, is the default local communications interface for almost all makes and models of inverter and battery systems. Whilst original equipment manufacturers (OEMs) may also offer WiFi connectivity and Internet hosted apps these add-on features may not always be available due to issues such as Internet outages, cloud hosting disruptions, lack of Internet infrastructure and even cybersecurity attacks.
The good news is that the local Modbus interface will continue to work even when the add-on features are out of action. If required, you can typically use both both the apps and Modbus at the same time.
Modbus has been designed to operate over many different physical layers like RS-232, RS-485, and Ethernet, allowing both serial and networked communications. The RS-485 variant, known as Modbus-RTU, is especially valued in noisy industrial environments because it can handle up to 32 devices on a single network with communication speeds of up to 115.2 kbps.
Modbus-RTU is the standard interface used by the AlphaMon Platform and your AlphaESS equipment. A straight-through CAT-5 or CAT-6 cable connects the AlphaMon Outdoor Module to the labelled “CAN/RS-485” or “Modbus” on your inverter’s wiring panel.
Digital and ADC Inputs
The AlphaMon Outdoor Module includes an integrated ADS1115 Analog to Digital Converter (ADC). This advanced chip can accurately read up to 4 analog data signals simultaneously with 16-Bit precision at a rate of 860 samples / second.
One application of this feature is AlphaMon’s ability to monitor up to 4 electrically isolated Current Transformers (CT). This emonLib schematic illustrates an interface between a CT transformer and the ADS1115 module.
Spare digital pins allow control of simple on/off devices such as load switching. One such application is AlphaMon’s 2-wire, auto-start feature for managed battery charging using a diesel, petrol or gas powered generator that supports the 2-wire feature.
