Configuration and Installation
Chapter 2
SCXI-1162 User Manual
2-10
© National Instruments Corporation
Front Connector Signal Descriptions
Pin
Signal Name
Description
B30, A30, B29,
In <0..3>, Vcc
Bank 0 input channels and Vcc
A29, C30
B26, A26, B25,
In <4..7>, Vcc
Bank 1 input channels and Vcc
A25, C26,
B22, A22, B21,
In <8..11>, Vcc
Bank 2 input channels and Vcc
A21, C22
B18, A18, B17,
In <12..15>, Vcc
Bank 3 input channels and Vcc
A17, C18
A13, B13, A14, In <16..19>, Vcc
Bank 4 input channels and Vcc
B14, C13
A9, B9, A10,
In <20..23>, Vcc
Bank 5 input channels and Vcc
B10, C9
A5, B5, A6, B6, In <24..27>, Vcc
Bank 6 input channels and Vcc
C5
A1, B1, A2, B2, In <28..32>, Vcc
Bank 7 input channels and Vcc
C1
C2, C6, C10,
NC (No Connect)
Unused pins
C14, C17, C21,
C25, C29
The optically isolated inputs of the SCXI-1162 consist of a light-emitting diode and a 360
Ω
series current limiting resistor. When current is pulled through an input, the diode emits light
which is sensed by a photosensitive circuit. When this circuit senses the light, it outputs a logic
low digital signal.
The SCXI-1162 consists of eight banks of four of these optically isolated digital inputs. Each
bank of inputs has a separate connection for the positive voltage (Vcc) of a 5 to 10 V supply.
The four inputs of each bank are referenced to the Vcc of that bank; therefore, for any bank of
inputs to work, a Vcc must be connected to that bank. An input will register a logic low when it
is driven to at least 4 V below its Vcc. Each input requires at most 7 mA of current to drive it to
this logic low state. An input will register a logic high when no current flows through it.
Figure 2-3 shows examples of how the SCXI-1162 can be connected to different signals. Only
bank 0 is shown; however, other banks are identical.
