National Instruments CFP-RLY-421 用户手册

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页码 14
© National Instruments Corp.
9
cFP-RLY-421
Upgrading the FieldPoint Firmware
You may need to upgrade the FieldPoint firmware when you add 
new I/O modules to the FieldPoint system. For information on 
determining which firmware you need and how to upgrade the 
firmware, go to 
ni.com/info
 and enter 
fpmatrix
.
Isolation and Safety Guidelines
Caution
Read the following information before 
attempting to connect the cFP-RLY-421 to any circuits 
that may contain hazardous voltages.
This section describes the isolation of the cFP-RLY-421 and its 
compliance with international safety standards. The field wiring 
connections are isolated from the backplane. The isolation is 
provided by the module, which has optical and galvanic isolation 
barriers designed and tested to protect against transient fault 
voltages of up to 2,300 V
rms
. The cFP-RLY-421 provides double 
insulation (compliant with IEC 61010-1) for working voltages of 
250 V
rms
1
. Safety standards (such as those published by UL and 
IEC) require the use of double insulation between hazardous 
voltages and any human-accessible parts or circuits.
Never try to use any isolation product between human-accessible 
parts (such as DIN rails or monitoring stations) and circuits that 
can be at hazardous potentials under normal conditions, unless the 
product is specifically designed for such an application, as is the 
cFP-RLY-421. 
Even though the cFP-RLY-421 is designed to handle applications 
with hazardous potentials, follow these guidelines to ensure a safe 
total system:
The cFP-RLY-421 has a safety isolation barrier between the 
I/O channels and the inter-module communication bus. There 
is no isolation between channels unless otherwise noted. If any 
of the channels on a module are wired at a hazardous potential, 
make sure that all other devices or circuits connected to that 
module are properly insulated from human contact.
1  
Working voltage is defined as the signal voltage plus the common-mode voltage. 
Common-mode voltage is the voltage of the module with respect to ground.