Data Read (Function Code: 03 Hex); Data Write/Broadcast Data Write (Function Code: 10 Hex); Error Check - Omron SYSDRIVE 3G3MV User Manual

Communications
·The following three functions codes are available.
Function code
03 Hex Data read
08 Hex Loop-back test
10 Hex Data write
Note 1. Do not use any code other than the above, otherwise the Inverter will detect a
communications error and return an error message.
Note 2. The Inverter uses the same function code for the response. If an error occurs,
however, the MSB of the function code will be set to 1. For example, if an error
occurs in a DSR message with function code 03, the function code of the
response will be 83.
H Communications Data
·Communications data is attached to the command. The contents and its arrangement
of communications data vary with the function code. For details, refer to 7-3 DSR Mes-
sage and Response.
H Error Check
The CRC-16 check code is the remainder (16 bits) when all of the message blocks
·
from the Slave address to the final communications data are connected in series, as
shown in the following diagram, and this data is divided by a fixed 17-digit binary num-
ber (1 1000 0000 0000 0101).
8 bits
Slave address
Function code
Start of communications data
End of communications data
7-12
Command name
The LSB of the Slave address is handled
as the MSB in CRC-16 calculation.
Note 1.
Note 2.
Note 3.
Reads the data of the specified register number.
Consecutive data of a maximum of 16 words (32
bytes) can be read.
The DSR message is returned as a response.
This command is used for checking the status of
communications.
The attached data in the format is written to the
specified register number. Consecutive data of a
maximum of 16 words (32 bytes) can be written.
Normally "0" is used as the initial value for CRC-16
calculations, but "--1" (16 bits all "1") is used here.
The CRC-16 code is calculated with the LSB of the
Slave address handled as the MSB, and the final
MSB of the communications data handled as the
LSB.
Calculate the CRC-16 code for responses from the
Slave as well, and compare it with the CRC-16
code in the response message.
Chapter 7
Description