SMC Networks HECR Series Communications Manual

MODBUS communication function
HECR 5-2
3) If necessary send a read request message to check if it was written correctly.
Message to notify the completion of the process is returned when the action for the
written request message is completed.
Send a read request message to confirm if the setting was written as requested.
4) Setting limit of circulating fluid temperature
When the circulating fluid set temperature is written by communication, the data is stored
in FRAM. When the product restarts, it restarts with the value which was set before the
restart. The number of times it is possible to overwrite FRAM is limited. Data is only
stored in FRAM when it receives a circulating fluid set temperature which is different from
the previous temperatures. Please check how many times it is possible to overwrite
FRAM, and avoid unnecessary changes of the circulating fluid set temperature during
communication
5.2 Communication specification
Refer to chapter 2 in regard to communication protocol.
• Protocol ･･･････････････････････････････････
• Master / Slave ･･･････････････････････････････････
• Letter code ･･･････････････････････････････････
• Slave address (Unit number) ･･････････････････････
• Function code ･･･････････････････････････････････
• Error check ･･･････････････････････････････････
• Data transfer direction ･････････････････････････
Modbus
Slave
ASCII
Select from 01H to 0FH
03H, 06H, 10H, 17H
LRC method
LSB
5.3 Setting and checking
5.3.1 List of Items to be Set and Checked
The table below explains the setting options of the MODBUS communication function.
Item
Explanation
Interface
Select RS-485 or RS-232C
RS-485 terminal unit
Set the terminal unit for RS-485
Communication protocol
Set the serial communication protocol
Control mode
Set the control mode of the product. Serial remote mode (SeriRem)
can be selected by setting the communication protocol to Modbus.
Slave address (Unit No.)
Set the slave address (Unit No.) of the unit
Communication speed
Set the communication speed of the Modbus protocol

SMC Networks HECR Series Specifications

General

Brand	SMC Networks
Model	HECR Series
Category	Chiller
Language	English