One of the dimensions of Industry 4.0 is to connect the various facilities in order to go back to the fundamental parameters, collect and process the alarms generated, and monitor performance through the regular measurement of fundamental indicators. And so to offer preventive maintenance, remote support of quality, or pro-active management of underlying industrial processes.
MODBUS - the reference industrial protocol
In the industrial world, the MODBUS protocol is largely supported by machines and installations in general. This protocol originally published by Modicon (now Schneider Electric) is the market standard. The success of MODBUS comes from the fact that it is simple to implement, open and free, and that it has been developed with industrial problems as a guide.
It makes it possible to connect industrial objects through a network, on the basis of the “Master” – “Slave” principle. A supervision software is Master and can thus interrogate or manipulate different machines, installations, devices, and more specifically to interact with notions like “coil“, “discreet input“, “input register” or “holding register“. Clearly, it is possible to modify the configurations / parameters of an installation connected in MODBUS, as well as to recover different measured elements (temperature, pressure level, energy consumed, units processed …).
There are basically 2 methods for connecting to MODBUS installations. Either based on a serial bus (RS485). This is called MODBUS RTU. Either via Ethernet. This is called MODBUS TCP.
IOT Software Platform - MODBUS Supervision and Monitoring
ModBus data processing
The software platform makes it possible to process the data collected. Input registers in MODBUS RTU mode (2 byte registers). Datawords in the MODBUS TCP configuration. This collected data is interpreted via the analysis and data processing module. They can also be aggregated.
The MODBUS data thus interpreted are then made available via configurable dashboards. Tables, lists, gauges, map representations, interactive widgets (close to a SCADA representation).
MODBUS REST APIs
All connected MODBUS data can be retrieved via REST APIs. Raw data (registers) or interpreted.
Hardware - How to connect to a MODBUS RTU or TCP network?
Connection in MODBUS TCP
The IOT Factory software platform makes it possible to configure a MODBUS agent that will connect, through a ROUTER (Router 4G for example, via a VPN), to the different MODBUS installations.
It is possible to configure in the MODBUS Agent the Datawords (the “modbus registers“) that one wishes to interrogate. These registers are then interpreted according to the type of machine attached, via a MODBUS converter that will translate the data into values, according to the manufacturer’s specifications. Machine status (Running, stopped, down, units produced, current temperature …)
These data are then available, for analyzes, dashboards, Alerts or via REST APIs.
Connection in MODBUS RTU
The software platform offers as standard 2 MODBUS RTU modems, which can go up input registers via the LORAWAN or NB-IOT network. These converters “MODBUS to LORAWAN” or “MODBUS to NB-IOT” allow to specify the “input registers” to read, the reading frequency (ex: every 5 minutes) and the sending frequency (for example every 30 minutes). minutes).
The advantage of these MODBUS converters is, of course, to be totally independent of the local network.