Omron CS1D DUPLEX SYSTEM - 10-2009 Operation Manual page 490

Online Replacement of I/O Units, Special I/O Units, and CPU Bus Units
454
2. Remove the Unit that is being replaced.
When the Unit Removal without a Programming Device function is select-
ed, one of the following non-fatal errors will be generated at this point, de-
pending on the type of Unit that was removed.
Unit type
Basic I/O Unit
Special I/O Unit
CPU Bus Unit
Note a) These non-fatal errors will not be generated when the Removal/
Addition of Units without a Programming Device function is select-
ed, unless the Unit is removed or mounted slowly.
b) If you don't want one of these non-fatal errors to be generated
when removing a Unit without a Programming Device, turn ON the
Maintenance Start Bit (A80015) before removing the Unit. When
this bit is ON, the errors above will not occur when the Unit is re-
moved.
c) Do not turn ON the Maintenance Start Bit (A80015) continuously
from the ladder program or other source. As long as the Mainte-
nance Start Bit is ON, errors will not be generated even if there are
Unit malfunctions, so the system may be adversely affected.
3. Replace the Unit.
Note a) If an Output Unit is being replaced, output ON status is retained
and the outputs will go back ON as soon as online replacement is
completed.
b) Replace the Unit with the same kind of Unit.
4. After the Unit is replaced, turn ON the Online Replacement Completed Bit
(A80215). (This step is not required with the Removal/Addition of Units
without a Programming Device function.)
Note a) The Online Replacement Completed Flag is required only when
the Unit Removal without a Programming Device function is being
used. When the Removal/Addition of Units without a Programming
Device function is being used, the data exchange is restarted au-
tomatically after the replacement Unit is mounted.
b) When the Online Replacement Completed Bit (A80215) is turned
ON, the replaced Unit will restart data exchange processing with
the CPU Unit.
When data exchange processing restarts, the Online Replace-
ment Completed Bit (A80215) will turned OFF. At the same time,
the Maintenance Start Bit (A80015) will be turned OFF automati-
cally if it is ON.
5. Check the replaced Unit's indicators and confirm that the Unit is operating
properly to complete the replacement procedure.
Non-fatal error
Basic I/O Unit error
Special I/O Unit error
CPU Bus Unit error
Section 11-4