Yamato Scientific BB600 Low Constant Temperature Water Bath - Manual (Page 34)

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Operation Method
RS485 Communication Function
4.5 Description of Codes
■ The following codes from ①STX, ②address to ⑩error type are represented by ASCII codes.
■ For ASCII codes, see "8. List of ASCII Codes."
■ For conversion into ASCII codes, see "5. Communication Examples."
① STX
This code is required for the receiving side to detect the head of a message. Add it at the head of
the character string to be transmitted.
② Address
This is the address of the unit with which the host computer communicates. The address within a
reply message from the unit indicates the unit that has transmitted the message.
③ Request
Enter the symbol "R" or "W."
R: To read data from the unit
W: To write data to the unit or save it in the unit
④ Identifier
This is the classification symbol (identifier) of the data to be read or written and represented by a
three-digit alphanumeric ASCII code. See "7. List of Identifiers/Commands."
⑤ Numeric data
This is the data to be read or written and always represented by five digits, irrespective of the type.
Negative data: The symbol "-" is at the highest digit.
Position of decimal point: Five-digit data does not include any decimal point.
Example) The meaning of the five-digit numeric data ００１０１ is shown in the table below.
Example Meaning of numeric data
When the temperature sensor is a
thermocouple
→ 101℃
Set temperature (SV1)
When the temperature sensor is
platinum
→ 10.1℃
Set time (TIM) → One hour and one minute
⑥ ETX
This code is required for the receiving side to detect the end of the message. Add it at the end of
the character string to be transmitted (except BCC).
⑦ BCC
This is the check code for error detection and takes the exclusive OR (EX-OR) of all characters
from STX to ETX. When "Enabled" is selected for BBC check among the communication settings
for the unit, this code (BCC) will not be included in the reply message.
⑧ ACK
This is an acknowledgement code and included and returned in the "reply message" from the unit
when no error is found in the received message.