Read/Write Operation Example - IMO HD2 IP Series Instruction Manual

HD2 IP55 High-ingress Protection Series
group of function code address data, the code is generated as follows:
For a normal response, the same code is returned.
For an exception response, the following code is returned:
In addition to the modification of the code, the slave returns a byte of exception code that
describes the cause of the exception. After receiving the exception response, the typical
processing of the master device is to transmit the request message again or modify the
command based on the fault information.
For example, to set the "Running command channel" (P00.01, the parameter address is 0001H)
of the inverter whose address is 01H to 03, the command is as follows:
01
inverter
address
But the setting range of the "Running command channel" is 0 to 2. The value 3 exceeds the
setting range. In this case, the inverter returns an error message response as shown in the
following:
The exception response code 86H (generated based on the MSB "1" of the write command
06H) indicates that it is an exception response to the write command (06H). The error code is
04H. From the preceding table, we can see that it indicates the error "Operation failure", which
means "The parameter is set to an invalid value in the write operation".

9.4.8 Read/Write operation example

For the formats of the read and write commands, see sections 9.4.1 and 9.4.2.
9.4.8.1 Read command 03H examples
Example 1: Read state word 1 of the inverter whose address is 01H. From the table of other
function parameters, we can see that the parameter address of state word 1 of the inverter is
2100H.
The read command transmitted to the inverter is as follows:
01
inverter
address
0 0 0 0 0 0 1 1 (03H in the hexadecimal form)
1 0 0 0 0 0 1 1 (83H in the hexadecimal form)
06 00 01
Write Parameter
command address
01 86
inverter Exception
address response code
03 21 00
Parameter
Read
address
command
00 03
Parameter
data
04 43 A3
Error code
00 01
Data quantity
-279-
Communication protocol
98 0B
CRC
CRC
8E 36
CRC