TOHO ELECTRONICS TTM200 User Manual
Page 11
11
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."
⑧ ACK
It is an acknowledge code. If a message received by this product is error-free, this code will
be incorporated in the "response message" from this product and returned.
⑨ NAK
It is a negative acknowledge code. If a "request message" received by this product is
error-ridden, this code will be incorporated in the "response message" from this product and
returned.
If the "request message" received is error-ridden, the error contents (⑩ ERR type) will be
incorporated in the "response message" from this product, following NAK.
⑩ ERR type
If a "request message" received from this product is error-ridden, the error contents (either
of the numbers in the table below) will be incorporated in the "response message" from this
product, following "⑨ NAK."
If there are two or more errors occurring at the same time, the largest error number will be
incorporated.
The table below indicates the error contents and classifications.
Error No.
Error contents in the "request message" received by this product
0
Instrument error (memory error or A/D conversion error)
1
The numerical data deviated from the "range of settings designated specifically with setting
items."
2
The change of requested items is disabled or there are no items to be read.
3
An ASCII code other than the numerical data was specified in the field of numerical data.
An ASCII code other than "0" and "-" was specified in the field of codes.
4
Format error
5
BCC error
6
Overrun error
7
Framing error
8
Parity error
9
A PV error occurred during AT. Or AT will not end 3 hours later.