Specifications

App6-28 Appendix 6 Universal Serial Communications
Data Items for Protocols
• Transmission control code
The transmission control codes are shown in the table below.
• Port number
Port numbers are used so that the host computer can identify each V series for access. The data
range is from 00H to 1FH (0 to 31) and is converted into two-digit ASCII code (HEX) before use.
The port number of the V series should be set on the V-SFT editor.
• Sum check code (SUM)
Data is added up (SUM), and the lower one byte (8 bits) of the sum is converted into the 2-digit
ASCII code (hexadecimal). A sum check code is shown below.
Example: Sum check will be as is shown below when data is transmitted as: command [WM]
(data writing), address [05AD] (1453), and memory data [OF2A] (3882) in
transmission mode [w/o CR/LF, w/ sum check].
However, in the case of an interrupt, data from ENQ to ETX is subject to a sum check.
• Error code
An error code is sent along with an NAK response.
An error code is transmitted as a two-digit ASCII code (HEX). For more information, refer to page
App6-41.
Signal Name Code (Hexadecimal) Contents
STX 02H Start of transmission block
ETX 03H End of transmission block
ENQ 05H Interrupt
ACK 06H Positive acknowledge
CR 0DH Carriage return
DLE 10H Change contents within a block
NAK 15H Negative acknowledge
LF 0AH Line feed
STX DLE ETX SUM
02
H 57H 4DH 10H 30H 35H 41H 44H 03H 34H 44H
"W" "M" "0" "5" "A" "D" "4" "D"
02H + 57H + 4DH + 10H + 30H + 35H + 41H + 44H + 30H + 30H + 30H + 31H
+ 30H + 46H + 32H + 41H + 03H =
4DH
30H 30H 30H 31H
"0" "0" "0" "1"
30H 46H 32H 41H
"0" "F" "2" "A"
Command Address Count Memory data