INVT Goodrive350-19 Series, Operation Manual

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Goodrive350-19 series VFD for crane Communication protocol
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32#
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Figure 10-5 Star connection
Use shielded cable, 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.
10.3.2 RTU
10.3.2.1 RTU communication frame structure
When a controller is set to use the RTU communication mode on a Modbus network, every byte (8
bits) in the message includes 2 hexadecimal characters (each includes 4 bits). Compared with the
ASCII mode, the RTU mode can send more data at the same baud rate.
Code system
·
1 start bit
·
7 or 8 data bits; the minimum valid bit is sent first. Each frame domain of 8 bits includes 2
hexadecimal characters (0
–9, A–F).
·
1 odd/even check bit; this bit is not provided if no check is needed.
·
1 end bit (with check performed), 2 bits (without check)
Error detection domain
·
Cyclic redundancy check (CRC)
The following tables provide the data formats.
11-bit character frame (Bits 1 to 8 are data bits)
Start bit BIT1 BIT2 BIT3 BIT4 BIT5 BIT6 BIT7 BIT8
Check
bit
End bit
10-bit character frame (Bits 1 to 7 are data bits)
Start bit BIT1 BIT2 BIT3 BIT4 BIT5 BIT6 BIT7
Check
bit
End bit