Cleveland Range inverter manual MODBUS-RTUCommunication, 5.6.3Detail Communication Protocol

Chapter 5 - MODBUS-RTU Communication

Example) Command Message (Request) for reading one address from address ‘3000’

				The Number
ENQ	Drive No.	CMD	Address	of address to	SUM	EOT
				read
05h	“01”	“R”	“3000”	“1”	“A7”	04h
1 byte	2 bytes	1 byte	4 bytes	1 byte	2 bytes	1 byte

SUM = ‘0’ + ‘1’ + ’R’ + ‘3’ + ‘0’ + ‘0’ + ‘0’ + ‘1’

=30h + 31h + 52h + 33h + 30h + 30h + 30h + 31h

=1A7h

5.6.3Detail Communication Protocol

Request for Read: Request for read ‘n’ numbers of WORD from address ‘XXXX’.

ENQ

Drive No.

CMD

Address

The number

SUM

EOT

of address to

read

05h

“01” ~

“R”

“XXXX”

“1” ~ “8” =

“XX”

04h

“1F”

n

1 byte

2 bytes

1 byte

4 bytes

1 byte

2 bytes

1 byte

Total byte = 12 bytes

The quotation marks (“ ”) mean character.

Acknowledge Response

ACK

Drive No.

CMD

Data

SUM

EOT

06h

“01” ~ “1F”

“R”

“XXXX”

“XX”

04h

1 byte

2 bytes

1byte

N * 4 bytes

2 bytes

1 byte

Total byte = 7 * n * 4 = max. 39 bytes

Negative Acknowledge Response

NAK

Drive No.

CMD

Error Code

SUM

EOT

15h

“01” ~ “1F”

“R”

“**”

“XX”

04h

1 byte

2 bytes

1 byte

2 bytes

2 bytes

1 byte

Total byte = 9 bytes

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