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HRX-OM-S010
Chapter 4 MODBUS communication function
4.2
Communication specification
HRS100/150 Series
4-2
4.1.2
Precautions for communicating
○Allow a suitable interval between requests.
To send request messages in series, wait for 100 msec. or longer after
receiving a response message from the product before sending the next
message.
○Retry (resend request message)
.
The response may not be returned due to noise. If no message is returned
1sec. after sending a request message, resend the request message.
○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.
○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
4.2 Communication specification
Table 4.2-1
Communication specification of MODBUS communication function
Item
Specification
Standard
Select from EIA RS-485
/
RS-232C
Communication speed
Select from 9600bps
/
19200bps
Data
・
bit length
7bit
Stop
・
bit length
1bit
Data transfer direction
LSB
Parity
Even parity
Letter code
ASCII mode
Slave address set range
Select from 1 to 99 address
Error check
LRC method
:
Default setting