Omron NT21 Reference Manual page 146

Touch Switches
Reference: In the case of (1) in the table above, even a bit whose status is retained by the
Symbol C-series PCs
None IR Area
H HR Area
A AR Area
L LR Area
TC Area,
T
Timer PVs
TU ---
TC Area,
C
Counter PVs
CU ---
W ---
TK ---
D DM Area
*2
EM Area ,
E
current bank
E0_ to
---
EC_
130
written. However, if the contents of the word are changed at the host during
display, they will be rewritten based on the contents before display.
If the screen is switched while a momentary touch switch is pressed, the touch
switch itself will disappear and the OFF status will be notified to the host.
Therefore, in the case of (1) in the table, all the bits in the word will be set to the
OFF status.
When using the host link, since writing in bit units is not possible, the statuses
of bits other than the notify bit in the word allocated for a momentary/set/reset
touch switch are not retained when the screen is switched.
If the status of a bit allocated for an alternate touch switch is changed other
than by touch switch operation — for example by Programming Console op-
eration — the correct operation of the alternate touch switch cannot be guaran-
teed from that point onward (the ON and OFF states may be transposed).
In the case of (3) and (4) in the table above, notification has no effect on the
other bits in the word.
KEEP instruction for ladder program self latch operation will be turned OFF. In
order to avoid this, allocate bits other than in the DM Area when using the NT link
also.
Allocation of the Notify Bit
The notification bit can be allocated in the following host (PC) areas.
Allocation CV-series PCs
OK CIO Area
OK ---
OK Auxiliary Area
OK ---
Timer Area,
No
Timer PVs
--- ---
Counter Area,
No
Counter PVs
--- ---
--- ---
--- ---
OK DM Area
EM Area,
OK
current bank
--- ---
*1: LR 00000 to LR 00199 are converted to CIO 01000 to CIO 01199.
*2: The EM Area is supported only by C200HX/HG/HE(-Z)E PCs.
*3: The EM Area current bank cannot be used in CS/CJ-series PCs when a 1:N NT
Link (standard or high-speed) is being used through a Serial Communications
Allocation CS/CJ-series PCs
OK CIO Area
--- HR Area
No AR Area
*1
--- LR Area
TC Area,
No
Timer PVs
TC Area,
---
Timer Completion Flags
TC Area,
No
Counter PVs
TC Area,
---
Counter Completion Flags
--- WR Area
--- Task Flags
OK DM Area
*3
Not for EM Area
Host Link (Current Bank)
EM Area,
---
EM banks 0 to C
Section 2-7
Allocation
OK
Not for
Host Link
OK
Not for
Host Link
No
Not for
Host Link
No
Not for
Host Link
Not for
Host Link
Not for
Host Link
OK
Not for
Host Link
Not for
Host Link