Omron VS mini J7 User Manual page 114

Message Communications Basic Format
Error Check
8 bits
Slave address
Function code
Start of communications data
End of communications data
100
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 number (1 1000 0000 0000 0101).
The LSB of the Slave address is handled as the MSB in CRC-16 calculation.
Chapter 7-3