INVT GD10-0R2G-2-B, Руководство по эксплуатации

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Goodrive10 Series Mini VFD Communication protocol
-87-
Use shielded cables, if possible, in multi-VFD connection. The baud rates, data bit check
settings, and other basic parameters of all the devices on the RS485 line must be set
consistently, and addresses cannot be repeated.
7.2.2 RTU mode
7.2.2.1 RTU communication frame format
If the controller is set to communicate by RTU mode in Modbus network every 8bit byte in
the message includes two 4Bit hex characters. Compared with ACSII mode, this mode can
send more data at the same baud rate.
Code system
• 1 start bit
• 7 or 8 digital bit, the minimum valid bit can be sent firstly. Every 8 bit frame includes two
hex characters (0...9, A...F)
• 1even/odd check bit . If there is no checkout, the even/odd check bit is inexistent.
• 1 stop bit (with checkout), or 2 bits (no checkout)
Error detection domain
• Cyclic redundancy check (CRC)
The following table describes the data format.
11-bit character frame (Bits 1 to 8 are data bits)
Start bit BIT1 BIT2 BIT3 BIT4 BIT5 BIT6 BIT7 BIT8
Check
bit
EStop
bit
10-bit character frame (Bits 1 to 7 are data bits)
Start bit BIT1 BIT2 BIT3 BIT4 BIT5 BIT6 BIT7
Check
bit
EStop
bit
In a character frame, only the data bits carry information. The start bit, check bit, and stop bit
are used to facilitate the transmission of the data bits to the destination device. In practical
applications, you must set the data bits, parity check bits, and stop bits consistently.
In RTU mode, the transmission of a new frame always starts from an idle time (the
transmission time of 3.5 bytes). On a network where the transmission rate is calculated
based on the baud rate, the transmission time of 3.5 bytes can be easily obtained. After the
idle time ends, the data domains are transmitted in the following sequence: slave address,
operation command code, data, and CRC check character. Each byte transmitted in each
domain includes 2 hexadecimal characters (0
–9, A–F). The network devices always monitor