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Pre-Commissioning
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If the chiller enters the Modbus remote mode, all the information can only be monitored through the HMI. Actual operation control (start / stop or
changing the set temperature) can only be performed through the external controller. To control from the HMI, change the control mode to “Local”.
Remote communication error CH10009 will occur when the communication is disconnected between the HMI and external controllers. When com-
munication is recovered, it will automatically resume. If the remote Modbus connection is not used, reset the power of the main PCB of the chiller to
cancel the alarm.
Modbus Interlock Protocol Details
The protocol details for Modbus interlock of external devices are:
• Physical layer: RS-485 serial line
• Mode: Modbus RTU mode
• Baud rate: 9,600
• Parity: None parity
• One (1) stop bit
• Applied function codes
Function Code Sub-function Function Name Start Address From Main Device
0x01 None Read Coil Register Address-1
0x02 None Read Discrete Input Register Address-10001
0x03 None Read Holding Register Address-40001
0x04 None Read Input Register Address-30001
0x05 None Write Single Coil Register Address-1
0x06 None Write Single Holding Register Address-40001
0xF1~FF Reserved for Exception Code - -
Figure 45: Applied Function Codes.
See the Modbus protocols in the following pages.
MODBUS PROTOCOL
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