SCXI-1303 Installation Guide
2
©
National Instruments Corporation
❑
SCXI chassis
❑
SCXI-1102/B/C or SCXI-1100 module
❑
One package of four 10 M
Ω
resistor networks
❑
No. 1 and No. 2 Phillips-head screwdrivers
❑
1
/
10
in. and
1
/
4
in. flathead screwdrivers
❑
Long-nose pliers
Changing Resistor Networks
Use long-nose pliers to remove or replace the resistor networks in the
sockets; be careful not to damage the network package. Make sure pin 1
of each network is in the correct position in the socket. Refer to Figure 4 to
locate pin 1 for each resistor network socket.
Each resistor network is labeled with descriptive numbers on the left front
side, and pin 1 is located directly beneath the darkened symbol within these
numbers. The 10
Ω
resistor network is labeled 100 (10
×
10
0
Ω
); the 10 M
Ω
resistor network is labeled 106 (10
×
10
6
Ω
). Figure 1 shows examples of
these resistors.
Figure 1.
Resistor Networks
Open Thermocouple Detection
The SCXI-1303 circuitry helps you detect an open thermocouple. To detect
whether any thermocouple is open, check whether the corresponding SCXI
module channel is saturated. The SCXI-1303 has pullup and bias resistors
that saturate the channel by ap5 V at the input of the open channel.
Notice that this will result in saturation to either of the positive or negative
rails.
SCXI-1102/B/C Module
You can replace the 10
Ω
bias resistor networks (factory shipping
configuration) in the SCXI-1303 with the 10 M
Ω
resistor networks
supplied in the kit. With the 10 M
Ω
resistor networks, it does not matter
Mfr. code
10x-1-100
Pin 1
Mfr. code
10x-1-106
Pin 1
a. 10
Ω
Resistor Network
b. 10 M
Ω
Resistor Network
Summary of Contents for SCXI-1303
Page 11: ......