Shihlin electric SL3 Series, Руководство пользователя

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Communication parameter group 07
PARAMETER DESCRIPTION 120

Communication format：
In general, Master sends Query Message to Slave, which returns Response Message to Master. During normal communication,
address codes and function codes are copied. During abnormal communication, function code bit7 is set to “1” (=H80), and
Data Byte is set to error code

Message compensation：
Format Start ① Address
②
Function
③
Data
④
Error check Stop
ASCII H3A
8bit 8bit n×8bit 2×8bit
0D 0A
RTU >=10ms >=10ms
Message Content
①Address
information group
Setting range: 0~254. 0 is for broadcast address, 1~254 for slave device (inverter) address.
07-01（P.36）is used to set the Slave device address when Master device sends information to the Slave
device and the Slave device replies information to Master device
②３Function
information group
At present, there are four functions. Slave device acts according to the request of Master device. If Master
device sets a function code other than the table below, Slave device will return an error response. Normal
function code will be returned when response is normal, and H80+ function code will be returned when
response is wrong.
Function name Function code Function description
Read multiple registers H03 Read Slave’s continuous register content.
Write single register H06 Write data into Slave’s single register.
Function diagnosis H08 Function diagnosis(only for communication check)
Write multiple registers H10 Data can be written to Slave’s multiple registers.
③Data information
group Change according to function code, including initial address, number of registers written and read, data
written, etc.
④Error checking
information group
ASCII is the check method for LRC, while RTU is the check method for CRC
Calculation of LRC check value in ASCII mode:
LRC check is relatively simple, which is used in ASCII mode and can detect all contents in the information domain except the
starting colon and the ending carriage return character, it superimpose each data to be transmitted according to bytes (not
ASCII code). If the obtained result is greater than hexadecimal H100, remove the excess part (for example, if hexadecimal
H136 is obtained, only retain H36), obtain the inverse code of the remaining part and add 1 to it.
Calculation of CRC check value in RTU mode:
1. Add a 16-bit register with every bit set to 1.
2. Perform an xor operation between the upper byte of the 16-bit register and the initial 8-bit byte, the result of which is put
into this 16-bit register.
3. Move this 16-bit register one bit to the right.
4. If the bit moved to the right (marked bit) is 1, perform an xor operation between the generated polynomial
1010000000000001 with this register. If the bit moved to the right is 0, 3 will be returned.
5. Repeat steps 3 and 4 until 8 bits are removed.
6. Perform an xor operation between another 8 bits with this 16-bit register.
7. Repeat steps 3 to 6 until all bytes of the message are performed xor operation with the 16-bit register and bit has been
moved for 8 times.
8. The content of this 16-bit register is the 2-byte CRC error check code, which will be added to the highest significant bit of
the message.
When adding CRC to the message, the low byte is added first, then the high byte.