Command and Response Frame Structure
Section 5-1
5-2
5-1
Command and Response Frame Structure
5-1-1
Command Frame Structure
The ID Controller continuously receives signals from STX to ETX, and executes the command when
the correct node number is received. If, after receiving an STX signal, another STX signal is re-
ceived before an ETX signal is received, the second STX signal is given command priority.
STX
Node No. Command Code
Option Text
BCC
“
oo
”
“
oo
”
ETX
1
2
2
1
1
Name
Description
STX
Indicates the beginning of a communication frame (text). Expressed by
ASCII code 02.
Node No.
Node number of the Controller
- The values from “00” to “09” can be set.
- No response is returned to the command with node numbers other than
the number set to the Controller.
Command code
Indicates the command that the Controller executes.
Refer to 5-2 Command List for command codes available.
Option
Makes specified optional settings or specifies read/write data.
Refer to each command format for details.
ETX
Indicates the end of a communication frame (text)
BCC
Block check character. The result of the horizontal parity calculation from
immediately after STX through ETX is expressed using one character.
Turn ON or OFF BCC using pin 8 on DIP switch 3.
Refer to 5-1-3 BCC Calculation Method for how BCC is calculated.
5-1-2
Response Frame Structure
The text of a response consists of a Retry flag, command code, response code, and text data.
Node No.
Response code
Text data
BCC
STX
“
oo
”
“
o
”
“
oo
”
“
oo
”
ETX
1
2
1
2
2
1
1
Name
Description
Retry Flag
In ACK/NACK control, when NACK is received and the previous response
is returned, the retry flag is set to “1”. In other cases, it is set to “0”.
Command code
The received command code is returned.
Response code
Indicates the state of the Controller after command execution.
Refer to 5-10 Response Code List.
Text data
Sent in response to specific commands.
For the content, refer to the frame structure of each command.
Retry
Flag
Command
code
