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Receiving Explicit Messages Section 9-2
CPU Unit Status Read (Service Code: 40 Hex)
This PLC Object service reads status details (operation status, operating
mode, fatal and non-fatal errors, etc.) from the CPU Unit.
Command Block
Note A body format of either 8 bits or 16 bits is possible.
Response Block
Parameters Service code (command, response): 40 Hex is specified for commands. For
responses, the highest bit will turn ON and C0 Hex will be returned.
Class ID (command): Always C4 (2F).
The class ID depends on the unit version. The class ID is C4 for unit version
2.0, and 2F for unit version 1.0.
Instance ID (command): Always 00 Hex.
Read data (response): The read data is given in the following table. The data
is returned after the service code in the order shown in the table (high to low).
• Operation status: Returns the operation status of the CPU Unit in 1-byte
(2-digit) hexadecimal.
The values of bits 3 to 6 are not fixed. Always mask them when address-
ing the status data.
00
(*)
40
C4
(2F)
(*)
Class ID
Instance ID
Service Code
The class ID depends on the unit version.
Version 2.0: The class ID is C4.
Version 1.0: The class ID is 2F.
C0
Service Code
Detailed status
Operation Status
RUN mode
Fatal error information (L)
Fatal error information (H)
Non-fatal error information (L)
Non-fatal error information (H)
Message exists/does not exist (L)
Message exists/does not exist (H)
Error code (L)
Error code (H)
Error message (16 bytes)