Samsung MIM-B19N Installation Manual page 10

Installing the Modbus Interface Module
CAUTION
sends a control command to the indoor units. Therefore, be sure to send a command to the Modbus master only when
control (operation on/off, temperature setting, etc.) is required.
If an identical command is issued consecutively, the same command is repeatedly sent to the indoor units.
To check whether the write command operates normally, send a write command to the master and then read the register
status.
response is received from the Modbus interface module.
Table 1. Example of signal flow
BMS
Indoor power on
Indoor power off
Indoor power on
Indoor power on
Indoor power on
10 English
Modbus
interface module
Response: Indoor power on Indoor Power on
Response: Indoor power off Indoor power off
Response: Indoor power on Indoor power on
Indoor power on
Response: Indoor power on
Response: Indoor power on Indoor power on
Indoor unit
Response: Power on
Response: Power off
Response: Power on
Response: Power on
Response: Power on
Remark