E6581315

3. Communication protocol

This communication protocol supports the TOSHIBA Inverter Protocol and part of MODBUS-RTU protocol.

Select the desired protocol from in the following communication protocol selection parameters (, ).

“Parameter Name and , Communication Number. 0807 and 0829” Data Range: 0, 1 (Initial value: 0)

0:TOSHIBA (Includes inter-drive communication)

1:MOUBUS-RTU

*A parameter change is reflected when the inverter is reset, such as in power off.

3.1.About the handling of received frames

To send and receive data frames, a frame synchronization system for locating the start and end points of each frame is defined with time for which no data is sent (time interval equivalent to the time required to send 3.5 bytes of data).

If no data is sent for the time required to send 3.5 bytes of data at the current transmission speed (approx. 4 ms or more at 9,600 bps or approx. 2 ms or more at 19,200/38,400 bps) after receipt of a frame, the entire frame is assumed to have reached and information in it is analyzed. For this rea- son, an interval corresponding to at least 3.5 bytes of data must be placed between frames.

When sending a significant data set using two or more frames, an interval corresponding to at least

1.5bytes of data must be placed between frames. If an interval corresponding to 1.5 bytes or more is not placed, the contents of a frame are analyzed separately from those of the other frames, and therefore communication are not carried out normally.

When two or more inverters on the same line are controlled individually one after another, not only data from the host computer to an inverter but also a response from an inverter to the host computer are transmitted to the other inverters on the line too. Therefore, an interval corresponding to at least

3.5bytes should be placed between the time when the host computer receives a response from an inverter and the time when it sends a frame to the next inverter. Otherwise the return frame received and the frame that is sent immediately after receipt of the return frame will be recognized as one frame and communication will not be carried out normally.

[Correct]

Frame A

3.5 bytes or more

[Wrong] If divided into two smaller frames, frame A cannot be received as a single frame.

Frame B

Note: An inverter cannot receive frame B before it finishes analyzing the contents of frame A.

Frame A (1/2)

Frame A (2/2)

1.5 bytes or more

Note: Correct if the interval corresponds

 

to less than 1.5 bytes of data.

Frame B

5

Page 5 Page 7
Page 6
Image 6
Toshiba RS485, VF-AS1 Series instruction manual Communication protocol, About the handling of received frames, Moubus-Rtu
Page 5 Page 7

RS485, VF-AS1 Series specifications

The Toshiba VF-AS1 Series represents a significant advancement in the realm of variable frequency drives (VFDs), designed for various industrial applications that demand precision, efficiency, and reliability. With support for RS485 communication, the VF-AS1 Series fosters seamless integration into complex automation systems, making it the perfect choice for modern manufacturing environments.

One of the standout features of the Toshiba VF-AS1 Series is its versatile communication capabilities. The built-in RS485 port allows for easy connectivity with a range of devices, including PLCs (Programmable Logic Controllers) and HMIs (Human-Machine Interfaces). This ensures real-time monitoring and control of motor functions, enhancing operational efficiency and data analysis.

The VF-AS1 Series is engineered with advanced control technologies that provide exceptional motor performance. It incorporates vector control algorithms that optimize torque and speed regulation for both standard and permanent magnet motors. This results in precise motor control across a wide range of speeds and load conditions, ensuring optimum performance and energy savings.

Another noteworthy characteristic is its user-friendly interface. The VF-AS1 features a clear LCD display that allows for easy navigation and configuration. This intuitive design minimizes the learning curve for operators and technicians, facilitating quick setup and adjustments. Additionally, the series supports various programming options, catering to both novice users and experienced professionals.

Energy efficiency is a key priority in the design of the VF-AS1 Series. The drives are equipped with energy-saving features that help reduce overall power consumption and operational costs. With built-in sleep modes and dynamic energy feedback, these drives optimize energy usage based on demand, making them suitable for both constant and variable load applications.

In terms of safety and protection, the VF-AS1 Series incorporates various built-in safeguards, including overvoltage, undervoltage, and overcurrent protection. This comprehensive approach to safety not only protects the drive itself but also ensures the longevity of connected equipment.

Overall, the Toshiba VF-AS1 Series, with its robust feature set, advanced technologies, and focus on energy efficiency, proves to be a reliable choice for a wide range of industrial applications. Its integration of RS485 communication allows for enhanced connectivity and control, making it an excellent solution for modern automation needs.
Top Page Image Contents