National Instruments cFP-RTD-124 User Manual

323349A-01 October 2002© 2002 National Instruments Corp. All rights reserved.FieldPoint™, National Instruments™, NI™, and ni.com™ are trademarks of N

FP-RTD-124 and cFP-RTD-124 10 ni.comconnections are isolated from the backplane and the inter-module communication bus. The isolation is provided by t

© National Instruments Corp. 11 FP-RTD-124 and cFP-RTD-124SpecificationsThese specifications are typical for the range –40 to 70 °C unless otherwise n

FP-RTD-124 and cFP-RTD-124 12 ni.comPhysical CharacteristicsIndicators ... Green POWER and READY indicatorsWeig

© National Instruments Corp. 13 FP-RTD-124 and cFP-RTD-124SafetyThe [c]FP-RTD-124 is designed to meet the requirements of the following standards for

FP-RTD-124 and cFP-RTD-124 14 ni.comMechanical DimensionsFigure 7 shows the mechanical dimensions of the FP-RTD-124 installed on a terminal base. Dime

© National Instruments Corp. 15 FP-RTD-124 and cFP-RTD-124Finland 09 725 725 11, France 01 48 14 24 24, Germany 089 741 31 30, Greece 01 42 96 427, Ho

FP-RTD-124 and cFP-RTD-124 2 ni.comInstalling the FP-RTD-124The FP-RTD-124 mounts on a FieldPoint terminal base (FP-TB-x). Hot plug-and-play enables y

© National Instruments Corp. 3 FP-RTD-124 and cFP-RTD-124To install the cFP-RTD-124, refer to Figure 2 and complete the following steps:1. Align the c

FP-RTD-124 and cFP-RTD-124 4 ni.comWiring the [c]FP-RTD-124The FP-TB-x terminal bases have connections for each of the eight input channels on the FP-

© National Instruments Corp. 5 FP-RTD-124 and cFP-RTD-124Figure 3 shows the input circuitry on one channel.Figure 3. FP-RTD-124 Input CircuitTaking M

FP-RTD-124 and cFP-RTD-124 6 ni.comnegative terminals (COM and SENSE–). Connect the third wire to the positive terminal (SENSE+). Use a short jumper w

© National Instruments Corp. 7 FP-RTD-124 and cFP-RTD-124Measuring ResistanceYou can use the [c]FP-RTD-124 to measure resistance in ohms. In this way,

FP-RTD-124 and cFP-RTD-124 8 ni.comUnfortunately, not all TCR values are as well defined by standards organizations, and the behavior of RTDs with the

© National Instruments Corp. 9 FP-RTD-124 and cFP-RTD-124Effects of Lead ResistanceThe [c]FP-RTD-124 measures resistance by driving a current through