Advantages of Using Fieldbus Data Transmission
The management of frequency converters is usually carried out using digital and analog inputs, while the drive status signals are transmitted via programmable relays. However, this approach has some drawbacks, particularly requiring additional communication lines and limiting the functionality of the frequency converter.
Today, it is possible to monitor and manage the frequency converter using a fieldbus. This allows for the use of a single cable (RS-485 twisted pair interface) to transmit encoded data using specific protocols.
Benefits of Using Fieldbus Data
The implementation of fieldbus data has several advantages:
- Significant reduction in cable costs.
- Reduction in the number of inputs/outputs of the automation controller required for managing and monitoring the frequency converter.
- Utilization of digital and analog inputs/outputs of the converter to expand the capabilities of automation controllers.
Supported Data Transmission Protocols
The integration of Danfoss frequency converters into automated control systems (information exchange via RS-485) can occur at the level of the programmable logic controller or at the SCADA level (Supervisory Control and Data Acquisition).
The system features various data transmission protocols supported by the VLT HVAC Basic Drive FC 101 and VLT Micro Drive FC 051 frequency converters via the RS-485 interface.
The protocol choice is based on the existing protocols in the system used by other control devices, such as engineering system controllers or refrigeration units.
If the required protocol is not available in the list of supported models, special converters or data gateways, which are widely available in the industrial automation equipment market, may be utilized.
Protocol Conversion
A gateway or converter not only performs protocol conversion but can also convert communication interfaces. For example, to connect the VLT Micro Drive FC 051 frequency converter to the BACnet Ethernet IP data transmission network, protocol converters (Gateway) may be used:
- Doc No: MG02K150 – VLT Micro Drive Design Guide. Section 8 – Installation and Configuration of RS-485.
- Doc No: MG02C550 – VLT Micro Drive Programming Guide. Section 5 – Parameter List.
- Doc No: MG18B150 – VLT HVAC Basic Drive Programming Guide. Section 38 – Communication and Additional Devices. Section 5 – Parameter List.
Additional information can be found on the specialized website of the Danfoss Power Electronics department wwwdrivesru.
Supported Protocols List for Danfoss Frequency Converter Models
Protocol | VLT HVAC Basic Drive FC 101 | VLT Micro Drive FC 051 |
FC | + | + |
ModBus RTU | + | + |
BACnet MSTP | + | - |
L&S FLN | + | - |
MetaSys N2 | + | - |