Omron SYSMAC CJ - REFERENCE MANUAL 01-2008 Reference Manual page 1080

Network Instructions
Explicit Message
Instructions
Features of Explicit
Message Instructions
Operation
Condition
1) Normal end
2) Error end a) When the explicit
message could not
be sent
b) When the explicit
message was sent
but an explicit error
response was
returned
The following instructions, which are used specially for explicit messages, are
called Explicit Message Instructions.
Instruction Name
EXPLT(720) EXPLICIT MES-
SAGE SEND
EGATR(721) EXPLICIT GET
ATTRIBUTE
ESATR(721) EXPLICIT SET
ATTRIBUTE
EGATR(721) EXPLICIT WORD
READ
EGATR(721) EXPLICIT WORD
WRITE
• Explicit Message Instructions do not require giving a 2801 hex FINS com-
mand and are much simpler to program than CMND(490).
• With the EXPLICIT GET/SET ATTRIBUTE instructions, entering the ser-
vice code is not required and only information from the class ID onward
needs to be entered.
• With the EXPLICIT WORD READ/WRITE instructions, the I/O memory
address in the local and remote CPU Units can be specified directly.
Code specifications for area types and hexadecimal word addresses are
not required. (These are required for CMND(490) instructions with service
code 1E (word data read) or 1F hex (word data write).)
This enables easy reading and writing of data between CPU Units using
explicit message communications (like SEND/RECV instructions for FINS
commands).
The Explicit Communications Error Flag is used to determine if communica-
tions ended normally or in error.
For error completions (i.e., when the flag is ON), the Communications Port
Error Flag for FINS commands is used to determine if the explicit message
was never sent (i.e., when the flag is ON) or if there was an error in the explicit
message that was sent (i.e., when the flag is OFF).
The Communications Port Completion Code will contain 0000 hex after a nor-
mal end, an explicit message error code after an explicit communications
error end, and a FINS message completion code after a FINS error end.
Explicit
Communications Error
Flag (A21300 to
A21307:
Communications port
No. 0 to 7)
OFF
ON
Outline
Sends an explicit message with any service
code. Note: Functionally, this instruction is the
same as sending CMND(490) with a FINS com-
mand code of 2801 hex.
Sends an explicit message with a service code
of 0E hex (GET ATTRIBUTE SINGLE).
Sends an explicit message with a service code
of 10 hex (SET ATTRIBUTE SINGLE).
Uses an explicit message to read data from a
CPU Unit.
Uses an explicit message to write data to a
CPU Unit.
Communications Port
Error Flag (A21900 to
A21907:
Communications port
No. 0 to 7)
OFF
ON
OFF
Section 3-25
Communications Port
Completion Code (A203
to A210:
Communications port
No. 0 to 7)
0000 hex
FINS messages comple-
tion code
Explicit message error
code
1041