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AC90 TENSION CONTROL FREQUENCY INVERTER MANUAL BASIC OPERATION AND TRIAL RUN
182
RTU Host machine command information
START
Transmission time of 3.5 bytes
Slave machine address
01H
Command code
08H
Detecting code high-order
00H
Detecting code low-order
00H
Data high-order
13H
Data low-order
88H
CRC CHK low-order
EDH
CRC CHK high-order
5DH
END
Transmission time of 3.5 bytes
RTU Slave machine responding information
(
normal
)
START
Transmission time of 3.5 bytes
Slave machine address
01H
Command code
08H
Detecting code high-order
00H
Detecting code low-order
00H
Data high-order
13H
Data low-order
88H
CRC CHK low-order
EDH
CRC CHK high-order
5DH
END
Transmission time of 3.5 bytes
RTU Slave machine responding information
(
abnormal
)
START
Transmission time of 3.5 bytes
slave machine address
01H
Command code
88H
Error code
03H
CRC CHK low-order
06H
CRC CHK high-order
01H
END
Transmission time of 3.5 bytes
Communication frame error check mode
The standard ModBus serial network adopts two kinds of error check mode: odd/even checking which is used to check
every character and CRC detecting which is used to check one frame of data.
1.
Odd-even checking
The users can configure the controller with odd or even checking, or no checking, what will determine how to set
odd/even checking in every character.
If odd /even checking have been allocated, "1" bit will be accounted to the bit number of each character (7 bits in ASCII
mode, 8 bits in RTU). For instance, the RTU character frame contains the following 8 bits: 1 1 0 0 0 1 0 1
There are 4 bits with number"1". If using the even checking, odd/even checking bit of the frame will be 0, then there are
still 4 bits with number"1". If using odd checking, odd/even checking bit of the frame will be 1, then there are 5 bits with
number"1".