National Instruments CFP-RLY-421 用户手册

Before you configure a FieldPoint system that uses a cFP-RLY-421 
module, calculate the total power consumption of the I/O modules 
on the FieldPoint bank. You can find the power requirement 
specification in the operating instructions for each I/O module. 
The maximum power the network module can supply is specified 
in the network module user manual. Make sure the total power 
requirement for all of the I/O modules in the bank is less than the 
maximum power available from the network module. 

Suppose you have a bank with a cFP-2000 network module, 
four cFP-RLY-421 modules, and four cFP-DI-301 modules. The 
cFP-2000 can supply up to 9 W. The cFP-RLY-421 requires 1.7 W, 
and cFP-DI-301 requires 0.325 W. The four cFP-RLY-421 and four 
cFP-DI-301 modules require a total of 8.1 W:

4 

× 1.7 W + 4 × 0.325 W = 8.1 W

This configuration meets the 9 W power requirement. 

The cFP-RLY-421

 

mounts on a Compact FieldPoint backplane 

(cFP-BP-x), which provides operating power to the module. 
Installing the cFP-RLY-421 onto a powered backplane does not 
disrupt the operation of the bank. 

To install the cFP-RLY-421, refer to Figure 1 and complete the 
following steps:

1. Align the captive screws on the cFP-RLY-421 with the holes 

on the backplane. The alignment keys on the cFP-RLY-421 
prevent backward insertion. 

2. Press firmly to seat the cFP-RLY-421 on the backplane.

3. Using a number 2 Phillips screwdriver with a shank of at least 

64 mm (2.5 in.) length, tighten the captive screws to 1.1 N

⋅ m 

(10 lb

⋅ in.) of torque. The nylon coating on the screws prevents 

them from loosening.