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Input
Diagram
Output
Diagram
MCU
+5V
1K
2.2K
Input
MCU
+5V
P
N
100
10K
Output
Appendix K
I/O Electrical Specifications
All
User
I/O
inputs
and
outputs
(except
limit
switch
inputs)
are
TTL
levels
(0
to
+5VDC.)
Outputs
are
normally
low,
and
can
sink
and
source
20
mA
max.
Limit
switch
inputs
are
optically
isolated.
Limit
inputs
operate
on
24VDC
through
a
10K
ohm
resistor
to
power
the
LED
in
the
optical
isolator
(see
Appendix
N
for
more
information.)
The
+5VDC
on
I/O,2
is
intended
for
use
with
additional
analog
input
circuitry.
Current
draw
should
not
exceed
75mA.
Never
directly
connect
a
VXM
I/O
to
an
inductive
load,
any
device
that
is
not
within
10
feet
of
the
VXM,
or
anything
not
powered
at
the
same
AC
source.
Damage
due
to
improperly
interfacing
VXM
controllers
to
other
devices
is
not
covered
under
the
warranty.
As
a
minimum
precaution
against
electrostatic
discharge
(ESD)
damage
follow
these
guidelines:
1.
Provide
the
shortest
conductive
path
possible
to
earth
ground
from
user
designed
panels
or
enclosures
that
have
switches
or
buttons
the
operator
will
come
in
contact
with.
2.
Use
metal
panels
and
enclosures
to
house
buttons
or
switches
electrically
bonded
to
a
protective
earth
ground.
3.
Use
shielded
cables
on
all
VXM
I/O.
4.
If
no
other
protective
earth
ground
is
available,
use
the
earth
ground
on
the
VXMs
Auxiliary
I/O
connector
shell
or
connector
shell
on
shielded
cable.
Inputs
have
a
2200
ohm
resistor
to
+5VDC,
and
are
activated
by
connecting
to
0V.
NOTE: When Input 4 (Stop) is held low (0V) program will not run.
*
Optically isolated relays may be required on all user I/Os to insure long term
reliable operation.
CAUTION:
* New feature: Only on VXM firmware versions 1.21 & up
!