11
Command/Response Formats Section 2-2
The following diagram shows the command format when there are more than
131 characters.
Note A “delimiter” is a CR code [CHR$(13)] sent as a single character to indicate
the middle of a command or response.
Partitioned Responses If a response is more than 131 characters long, the response from the PLC is
partitioned by returning a delimiter (CR code, CHR$(13)) instead of a termina-
tor at the end of each frame until the last one. A terminator is returned at the
end of the last frame.
In the following example procedure, the response is partitioned into three
frames.
1,2,3... 1. When the PLC receives the command frame from the host computer, it re-
turns response frame 1 with a delimiter (CR) at the end to the host com-
puter.
2. Only a delimiter (CR) is sent from the host computer to the PLC.
3. When the PLC receives this delimiter (CR), it returns response frame 2
with a delimiter (CR) at the end to the host computer.
4. Only a delimiter (CR) is sent from the host computer to the PLC.
5. When the PLC receives this delimiter (CR), it returns response frame 3
with a terminator (*CR) at the end to the host computer.
128 characters max. 128 characters max.
PLC
@Unit number
Header code
Command frame 1 Command frame 2 Command frame 3
Res
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