Omron CJ - REFERENCE MANUAL 07-2009 User Manual

9
Command/Response Formats Section 2-2
the following transmissions until the number of words set in the command has
been processed.
The frame formats for Host Link commands sent from a host computer and
responses returned by the PLC receiving the commands are explained in the
following section.
2-2 Command/Response Formats
Single-frame Commands If a command is not more than 131 characters long, communications can be
completed by sending a single command frame. This is called a “single-frame
command.”
Command Frame Format
• @: Must be attached at the beginning of the command.
• Unit number: Set in BCD from 0 to 31 for each Host Link Unit.
• Header code: Specified in two characters.
• Text: Set parameters corresponding to command code.
• FCS: Calculate 2-character FCS (frame check sequence) at host
computer. For details on calculating FCS, refer to FCS Cal-
culations later in this section.
• Terminator: Set “*” and CR (CHR$(13)) as two characters to indicate
the end of the command.
Single-frame Response If a response is not more than 131 characters long, the communications can
be completed by returning one response frame. This is called a “single-frame
response.”
Response Frame Format
• @: Must be attached at the beginning of the response.
• Unit number: Set in BCD from 0 to 31 for each Host Link Unit.
• Header code: The command code that was received is returned.
• End code: The results (error status, etc.) of command execution is
returned.
• Text: Returned only if there is read data.
Unit number (BCD)
Header code
Text
FCS
Terminator
Unit number
(
BCD
)
End code (hexadecimal)
Text
FCS
Terminator
Header code

Omron CJ - REFERENCE MANUAL 07-2009 Specifications

General

Category	Computer Hardware
Manufacturer	Omron
Model	CJ
Document Type	REFERENCE MANUAL
Publication Date	07-2009

Summary

Manual Usage and Compliance

Warranty and Limitations of Liability

Outlines OMRON's product warranty terms and limitations of liability.

Precautions

Safety Precautions

Emphasizes critical safety measures for PLC use, including power handling and unit disassembly avoidance.

Operating Environment Precautions

Details precautions for PLC system operation in various environments to ensure reliability and prevent malfunction.

Application Precautions

Lists essential safety and operational precautions for PLC system applications, covering grounding and component handling.

Section 2: Overview of C-mode Commands

2-1 C-mode Commands

Explains C-mode (Host Link) commands as a serial communication system between PLC and host computer.

Section 3: Overview of FINS Commands

3-1 FINS Commands

Section 4: C-mode Commands

4-1 C-mode Command List

4-3 C-mode Command Details

Offers detailed descriptions of individual C-mode commands, including format, parameters, limitations, and execution conditions.