|Factory automation applications must be equipped to handle and monitor the myriads of information from attached devices. For plastic manufacturing applications, the boiler control system plays a critical role by gathering and regulating information to ensure production is accurate and smooth. In this particular case, the customer combines eight subsystems that include power meters, water meters, alarm output, displays, and I/O status to be controlled by several intelligent controllers with Modbus RTU interface. The Modbus TCP protocol is used for this application due to the distance.
• Modbus serial to Modbus TCP translation
• Multiple slaves/masters support
• Automatic Modbus TCP response time detection
|Moxa's MGate MB3000 series, a serial to Ethernet Modbus gateway, was selected for their system. For this application, PLCs control the boiler system and intelligent controllers are responsible for retrieving information from the boiler and subsystems. When the control server (IPC) needs to acquire data from the boiler, the intelligent controllers with Modbus RTU interface will retrieve data from the boiler.
The command is sent in Modbus TCP packet format through the Local Area Network (LAN) and received by the MB3270. The MB3270 would then convert the packet into Modbus RTU messages for the intelligent controller to send to the remote control server via Modbus TCP. Finally, the intelligent controller receives the command from the IPC and relays the data by using Modbus TCP communication. Normally, PLCs and intelligent controllers control and monitor information separately. This unique architecture will ensure fast retrieval of real time data and allows for immediate alert if the primary communication (PLC) is down.
Moxa's MGate MB3270 offers high flexibility. Features that benefit boiler control systems are:
• Cascading Ethernet ports for easy wiring
• Response timeout auto detection to define the suitable timeout value
• Redundant power inputs minimize the risk of data loss in the event of power failures.
Today, more and more boiler control systems are being equipped with Moxa's MGate MB3000 series Modbus gateways.
MGate MB3170/MGate MB3270 Series
1 and 2-port advanced serial-to-Ethernet Modbus gateways
|Mature (technology has been on the market for > 5 years)|