Project Overview:

• In a Data Center there were about 4-5 VFDs (Variable Frequency Drive) and they needed to be controlled and monitored using MQTT protocol.

Initial Situation:

• VFDs were looped on RS485 Port and provided output in Modbus RTU (RS485) Protocol.
• The monitoring and control system that was cloud based only supported MQTT protocol.

Customer Requirement:

• Customer wanted to monitor and control VFDs data like Voltage, Current and Frequency from cloud.
• The VFDs work on Modbus RTU Protocol and Cloud API understands MQTT. Therefore, a direct exchange of data between them was not possible.

Solution Provided:

• ProtoConvert suggested a Gateway in which we can get the data from all the VFDs on RTU and post it on MQTT Broker.

Note: Client had purchased MQTT Broker Subscription

• The customer’s monitoring system subscribed Parameter tags on MQTT Broker.
• With the help of ProtoConvert Gateway, customer could monitor and control Data Center’s VFD data via MQTT Broker.
• The customer’s monitoring system could send back commands to update the Parameters on MQTT Broker.
• ProtoConvert Gateway had subscribed to these Parameter Values and on change relayed the commands on Modbus RTU enabled VFDs.

Result:

• Thus using the ProtoConvert Modbus RTU / MQTT gateway the integration of modbus RTU based VFDs with a cloud based monitoring system (that supported MQTT) was achieved.

Keywords:

• VFD (Variable Frequency Drive),
• MQTT Protocol,
• MQTT Broker,
• Data Center,
• API (Application Program Interface),
• Voltage,
• Current,
• Frequency,
• Modbus RTU Protocol,
• Parameter Tags,
• Publisher,
• Subscriber