Omron SYSMAC CJ1W-EIP21 - Manual (Page 282)

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Receiving Explicit Messages Section 9-2
• Message Exists/Does Not Exist: When the MSG instruction is executed
by the CPU Unit, the bit corresponding to the message number will turn
ON and be returned in 2 bytes (from low to high bytes).
• Error Code: The highest priority error code of the errors existing when
the command is executed will be returned in 2-byte decimal (from low to
high bytes). If there are no errors, the error code will be 0000.
Note For information on the severity of error codes, refer to the CS1 Series
CPU Unit Operation Manual (W339) or the CJ Series CPU Unit Op-
eration Manual (W393).
• Error Messages: If the above error codes have occurred when FAL/FALS
instructions are executed with registered messages, those messages are
returned in 16-byte ASCII. If there are no registered messages or if the
error codes have not occurred due to execution of FAL/FALS instructions,
the code is returned in ASCII with 20 Hex (space) in 16 bytes.
Byte Data Read (Service Code: 1C Hex)
Byte Data Read reads any I/O memory area data in a CPU Unit. The read
word data is in byte units. The response block data is returned in low-to-high
byte order.
Command Block
Note A body format of either 8 bits or 16 bits is possible.
Response Block
Parameters Service code (command, response): 1C Hex is specified for commands.
For responses, the highest bit will turn ON and 9C Hex will be returned.
Message No. 0 (1: exists; 0: does not exist)
Message No. 1 (1: exists; 0: does not exist)
Message No. 2 (1: exists; 0: does not exist)
Message No. 3 (1: exists; 0: does not exist)
Message No. 4 (1: exists; 0: does not exist)
Message No. 5 (1: exists; 0: does not exist)
Message No. 6 (1: exists; 0: does not exist)
Message No. 7 (1: exists; 0: does not exist)
1C
C4
(2F)
(*) (*)
Class ID Address L
Instance ID
Service Code
No. of bytes read
Address H
The class ID depends on the unit version.
Version 2.0: The class ID is C4.
Version 1.0: The class ID is 2F.
9C
Service Code
Word data H
Word data L
Word data H
Word data L
Read data (200 bytes max.)