Chapter 4: Programming 4-11
NCR USB DynaKey Control
NCRUsbKeyBoardCtl
is
an
ActiveX
control
that
contains
a
method
for
setting
the
key
clicks
SetClicks
,
and
a
method
for
downloading
the
key
translation
matrix
information,
SetKeyMatrix.
The
SetClicks
method
examines
all
currently
‐
enumerated
HID
devices,
finds
those
with
a
Vendor
‐
ID
equal
to
NCR’s
assigned
Vendor
ID
(0x0404).
Among
all
qualified
devices
found,
each
device
is
searched
for
a
KEY_CLICK_INFO
feature
report
that
contains
Volume
,
Frequency
,
and
Duration
usages.
When
a
matching
device
is
found,
that
device’s
product
ID
(PID)
is
used
to
locate
keyclick
values
within
the
Registry.
The
values
found
in
the
registry
are
sent
to
the
device
in
the
KEY_CLICK_INFO
feature
report.
Each
time
SetClicks
is
invoked,
it
reads
Volume
,
Frequenc
y,
and
Duration
keyclick
parameters
from
the
registry.
If
these
parameters
are
not
found
in
the
registry,
default
values
are
written
to
the
registry,
and
these
default
values
are
used.
This
causes
the
registry
to
contain
the
values
most
recently
sent
to
NCR
HID
KeyClick
devices.
The
default
values
for
Volume,
Frequency,
and
Duration,
SetUsbKeyClick
are
15,
1318,
and
16,
respectively.
The
SetKeyMatrix
method
examines
all
currently
‐
enumerated
HID
devices,
finds
those
with
a
Vendor
‐
ID
equal
to
NCR’s
assigned
Vendor
ID
(0x0404).
Among
all
qualified
devices
found,
each
device
is
searched
for
a
KEYBOARD_MAP
feature
report
that
contains
an
array
of
KEY_MATRIX_USAGE
usages,
When
a
matching
device
is
found,
that
device’s
PID
is
used
to
locate
Key
Matrix
entries
in
the
Registry.
If
no
Key
Matrix
values
are
found
for
that
specific
PID,
no
Key
Matrix
download
is
performed.
