BONFIGLIOLI Vectron Agile Communications Manual page 32

Exception Response:
Start Frame (RTU oder ASCII mode)
Address
Error Code
Exception Code
CRC or LRC & Endframe
Start Address
This field is used to store the parameter number and data set number. The parameter number ranges
from 0 – 1599 and is stored in the lower 12 bits; the data set number ranges from 0 – 9 and is stored
in the upper 4 bits.
e.g.: Parameter 372 (hex. 0x174), data set 2 (hex. 0x2) is stored as hex. 0x2174.
Data Set
Bits 15 14
For the above example:
Hex. 0 0
Bin. 2
No. of Registers
This field is used to store the 32-bit parameter value.
Note:
Parameter Values with decimal places are transferred without the decimal point. Depending on the
number of decimal places, the values are multiplied by 10, 100 or 1000.
Example:
A frequency value of 100.25 Hz is to be transmitted. The numerical value actually transmitted is
10025, which corresponds to 0x2729 in HEX format.
Exception Code
The following exception codes can occur:
2 ILLEGAL DATA ADDRESS
3 ILLEGAL DATA VALUE
4 SLAVE DEVICE FAILURE
Exception Codes are described in detail in Chapter 7.3.9 "Exception Codes".
Example of a Modbus ASCII telegram see chapter 9.2.2.2.
Example of a Modbus RTU telegram see chapter 9.1.2.39.1.2.3.
32
1 Byte
1 Byte
1 Byte
Start Address
13 12 11 10 9
1 0 0 0 0
1
− Parameter unknown
− No. of bytes in the data field too small or too large
− Error on reading the parameter
1 – 0xF7 (=247)
0xE4
2, 3 or 4
Parameter number
8 7 6 5 4
1 0 1 1 1
7
Modbus Agile
3 2 1 0
0 1 0 0
4
Protocol
02/2011