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Chapter 1
Getting Started with the cDAQ Chassis
Figure 1-8.
Power Screw Terminal Connector Plug
Caution
Do
not
tighten or loosen the terminal screws on the power connector while
the power is on.
4.
Connect the positive lead of the primary power source to the V1 terminal of the power
connector plug and tighten the terminal screw to 0.5 N · m (4.4 lb · in.) of torque.
5.
Connect the negative lead of the primary power source to one of the C terminals of the
power screw terminal connector plug and tighten the terminal screw to 0.5 N · m
(4.4 lb · in.) of torque.
6.
Optionally, you can connect the positive lead of a secondary power source to the V2
terminal and the negative lead to the other C terminal.
7.
Install the power connector plug on the front panel of the cDAQ chassis and tighten the
connector screws to 0.5 N · m (4.4 lb · in.) of torque.
8.
Turn on the external power source(s).
The cDAQ chassis uses V1 if the voltage across V1 and C is 9 V or greater. If the V1-to-C
voltage drops below 9 V, the cDAQ chassis switches to V2. If the V2-to-C voltage is less than
9 V, operation may be interrupted.
Note
If the cDAQ chassis is using V1 and a secondary power source is connected
to V2, there is a small leakage current on V2. The leakage current depends on the
V2-to-C voltage. Refer to the
Power Requirements
section of the specifications
document for your cDAQ chassis for nominal values of this leakage current.
If the power source is connected to the power connector using long wiring with high DC
resistance, the voltage at the power connector may be significantly lower than the specified
voltage of the power source.
The C terminals are internally connected to each other but are not connected to chassis ground.
You can connect the C terminals to chassis ground externally. Refer to the
Power Requirements
section of the specifications document for your cDAQ chassis for information about the power
supply input range. Refer to the
Safety Voltages
section of the specifications document for your
cDAQ chassis for information about the maximum voltage from terminal to chassis ground.
1
Connector Screws
2
Terminal Screw
1
1
2