Communication Guide, ©ComAp – March 2014 113
IGS-NT Communication Guide 03-2014.pdf
Read Multiple Registers
Query
Communication object number
- upper byte (MSB)
- lower byte (LSB)
See List of communication
objects
Communication object length expressed by the number of registers
- upper byte (MSB)
- lower byte (LSB)
Check field CRC
- lower byte (LSB)
- upper byte (MSB)
See Check field calculation
Standard response
Length of read data in bytes (L)
Data of the 1st register
- upper byte (MSB)
- lower byte (LSB)
Data of the 2nd register
- upper byte (MSB)
- lower byte (LSB)
Data of the last register
- upper byte (MSB)
- lower byte (LSB)
Check field CRC
- lower byte (LSB)
- upper byte (MSB)
See Check field calculation
Exceptional response
Check field CRC
- lower byte (LSB)
- upper byte (MSB)
See Check field calculation
Write Single Register
Query
Communication object number
- upper byte (MSB)
- lower byte (LSB)
See List of communication
objects
Data
- upper byte (MSB)
- lower byte (LSB)
Check field CRC
- lower byte (LSB)
- upper byte (MSB)
See Check field calculation
Standard response