Omron CJ - INSTRUCTIONS REFERENCE MANUAL 07-2009 Reference Manual page 813

3. Instructions
Precaution
• DLNK(226) refreshes data between the CPU Unit and specified CPU Bus Unit. Some time is required
for the data exchange with the CPU Bus Unit (for example, a data link with a Controller Link Unit).
• If the specified CPU Bus Unit is exchanging data, DLNK(226) will not be executed and the Equals
Flag will be turned OFF. We recommend programming the execution conditions shown below so that
the execution of DLNK(226) will be retried automatically.
Execution condition
a
• I/O refreshing will not be performed if a CPU Bus Unit Error (A402.07) or CPU Bus Unit Setup Error
(A402.03) has occurred in the specified CPU Bus Unit.
• I/O refreshing will be stopped if an I/O Bus Error occurs while I/O refreshing is being performed by
DLNK(226).
Sample program
When CIO 0.00 is ON in the following example, DLNK(226) performs immediate I/O refreshing (in this
case, data link refreshing within the PLC) for the CPU Bus Unit with unit number 1 (in this case, a
Controller Link Unit).
If I/O refreshing cannot be performed because the Controller Link Unit is refreshing data, the Equals
Flag will be turned OFF causing W0.01 to be turned ON so that the instruction execution will be retried
in the next cycle. When the I/O refreshing is completed normally, the Equals Flag will be turned ON and
the instruction will not be retried in the next cycle.
W0.00
0.00
W0.01
0.00
DLNK
Data link area
776
b
Equals Flag
Equals Flag
DLNK
&1
W0.01
Equals Flag
W0.00
Equals Flag
Controller Link Unit
with unit number 1
Refresh
&1
DLNK
N
a
b
Data link refreshing
Controller Link
CS/CJ/NSJ Series Instructions Reference Manual (W474)