Measurement Computing CIO-DIO24 - Manual (Page 15)

CIO-DIO24 User's Guide Functional Details
2.2 K SIP installed for pull-up
2.2 K SIP Dot
+5 VDC
HI
LO
(GND)
n7
U
s
er
C
on
n
ec
to
r
Di
g
it
a
l I
/O
L
in
e
s
n5
n4
n3
n2
n1
n0
n6
COM
Digital
I/O
Port
n = A, B, or C
2.2 K SIP
Dot
+5 VDC
HI
LO
(GND)
n7
U
s
er
C
on
n
ec
to
r
Di
g
it
a
l I
/O
L
in
e
s
n5
n4
n3
n2
n1
n0
n6
COM
2.2 K SIP installed for pull-down
Digital
I/O
Port
n = A, B, or C
Figure 9. Pull-up and pull-down resistor SIPs schematic
To pull-up lines, orient the SIP with the common pin (dot) toward the
HI
end; to pull-down, install the resistor
with the common pin in the
LO
hole.
When installing pull-up and pull-down resistor SIP packs, we recommend using 2.2K, eight-resistor Single
Inline Packages (MCC part number SP-K2.29C). Use a different value only if necessary.
Unconnected inputs float
Unconnected inputs typically float high, but not reliably. If you are using a CIO-DIO24 for input and have
unconnected inputs, ignore the data from those lines. You do not have to terminate input lines. Unconnected
lines will not affect the performance of connected lines. Mask out any unconnected bits in software.
Digital I/O Isolation
To provide external signal conditioning and isolation, you can connect the CIO-DIO24 to a CIO-ERB24 or
SSR-RACK24. The CIO-ERB24 provides 24 Form C electromechanical relays. The SSR-RACK24 is a
mounting rack for 24 solid-state relays.
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