TOHO ELECTRONICS TTX-700 - Manual (Page 11)

3.5 Description of codes
n The codes from ① STX, ② address to ⑩ ERR as indicated below are expressed in ASCII
codes.
n For the ASCII codes, see "9. Table of ASCII codes."
n For conversion to ASCII codes, see "4. Examples of TOHO communications."
① STX
This code is needed for the receiver to detect the top of the message. It is affixed to the top
of a character string to be sent.
② Address
This is the address of the party (this product) with whom a high-level computer
communicates. The address in the response message from this product indicates the sender
of the response message. Note that, when CH2 is used, two addresses are occupied. (Setting
ADR to 1 causes this product to occupy addresses 1 and 2.)
③ Contents requested
Enter a code R or W.
R: to read data from this product
W: to write or store data in this product
④ Identifier
An identifier is a classification code (identifier) for data to be read or written and expressed
in a three-digit alphanumerical ASCII code. See "10. Table of identifiers (codes)."
⑤ Numerical data
At the time of writing or reading, 5-digit numerical data can be written.
Example: The table below indicates the significances of 5-digit numerical data 00010.
Example Significance of the value
Proportional band (P)
→
1.0%
Data (PV), etc, whose decimal point can be shifted
When the decimal point setting (DP) is 0 10
When the decimal point setting (DP) is 0.1 1.0
If DP = 0.1, the numerical data "12000" means 1200.0. In the case of text data, it is "□□INP." (The □
is a space.)
⑥ ETX
This code is needed for the receiver to detect the end of a message. It is affixed to the end of
a character string to be sent (except for BCC).
⑦ BCC
This is a check code for error detection and is the exclusive OR (EX-OR) of all characters
from STX to ETX.
If the BCC check is set to "Disabled" in the communications settings in this product, this
code (BCC) will not be incorporated in the response message. See "2. Settings regarding
TOHO communications."
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