Download means that the master sends a command to write a value to the slave object. If
downloaded to a non-existent object, the master will generate an error.
The data format from the master
⚫
Function data Specifies the direction and size of the data transfer
23(0x16)
Sending
4
Bits of data
(bytes 4...7
include
32 bits)
2B(0x16)
Sending
2
Bits of data
(bytes 4...5
include
16 bits)
2F(0x16)
sending
1
Bit of data
(bytes 4
include
8
bits)
⚫
Indexes
The address of the sending object, 16 bits
⚫
Subindexes
Subaddress of the sending object, 8 bits
⚫
Data Sending data
The order of the four bits in the data is that the high bit is in the back and the low bit is in the front.
⚫
example:
Write 600rpm to the "target speed" of the slave station, the internal unit of 2FF0.09 is rpm, 600 is
decimal, and hexadecimal is 258. Since the length of the object to be written is 4 bits, but the
calculation result is only two Bit, should be filled with 0 in the high order, so the final result = 00 00
02 58
Slave response data format
⚫
Function code: display slave response
60(0x16) Data sending successed
80(0x16)
Error from Bit
4…7
⚫
Indexes
The address of the sending object, 16bits, same as master’s
⚫
Subindexes
Subaddress of the sending object, 8bits, same as master’s
⚫
Keeping Keeping data
B:upload(from slave to master)
Upload means that the master sends a command to read the slave object address.
Uploading a non-existent address will cause an error to the master.
Sending data from master
⚫
Function code Define the direction of data transfer
40(0x16) Read data