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FieldPoint Operating Instructions
CFP-RLY-421
Eight-Channel SPST Relay Module
These operating instructions describe how to install and use the
National Instruments cFP-RLY-421 relay module. For details on
configuring and accessing the cFP-RLY-421 over a network, refer
to the user manual for the FieldPoint network module you are
using.
Features
The cFP-RLY-421 is a Compact FieldPoint relay output module
with the following features:
• Eight single-pole single-throw (SPST) relay channels
Swi
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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.
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5 2 1 4 5 4 3 1 cFP I/O Module 4 Screw Holes 2 Captive Screws 5 cFP Backplane 3 cFP Controller Module Figure 1. Installing the cFP-RLY-421 Wiring the cFP-RLY-421 The cFP-CB-x connector block has connections for each of the eight cFP-RLY-421 relay channels and for an external supply to power field devices. If you are using the cFP-RLY-421 in a hazardous voltage application, you must use the cFP-CB-1 connector block or a suitable hazardous voltage cable. A hazardous voltage is a voltage grea
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Table 1 lists the terminal assignments for the signals of each channel. Table 1. Terminal Assignments Terminal Numbers Channel NO IC 0 1 2 1 3 4 2 5 6 3 7 8 4 9 10 5 11 12 6 13 14 7 15 16 All of the COM terminals are connected internally and all of the V terminals are connected internally. NI does not recommend SUP using them with the cFP-RLY-421. Table 2. V and COM Terminal Assignments SUP V COM SUP 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Caution Cascading power between two modules
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Connecting Loads to the cFP-RLY-421 Wire an external power supply to the load and IC terminal of the individual channel as shown in Figure 2. This method of wiring keeps the electrical connections of the cFP-RLY-421 within safe current limits. V C V SUP NO Sourcing + Load or IC – AC COM To next channel cFP-RLY-421 Figure 2. Connecting a Load The cFP-RLY-421 has eight SPST (Single-Pole-Single-Throw) electromechanical relays. The power-up state is off (open) to ensure safe installation. In
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In addition, the cFP-RLY-421 has internal protection MOVs to prevent excessively high voltage from being applied across the contacts. The MOVs are located between the NO and IC contacts of each relay. However, National Instruments still recommends the use of a protection circuit across an inductive load. The flyback protection causes a small leakage current, which is detailed in the Specifications section. Guidelines for Selecting Contact 1 Protection Circuits Proper selection is critical
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Diode Circuit Diagram Notes Use in DC applications only. Compared to RC type, circuit delays release time (2 to 5 times values stated in catalog). For larger voltages, use diode with reverse breakdown 10 times circuit voltage and forward load circuit. Load For smaller voltages, use reverse breakdown voltage of 2 to 3 times power supply voltage. CR Circuits Diagram Notes Circuit A is suitable for AC or DC applications, but if used with AC voltage, impedance of the load should be smalle
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In-Rush Current The type of load and its in-rush current characteristics, together with switching frequency, can cause contact welding. For loads with in-rush current, measure the steady state current and in-rush current to determine the proper relay. Some typical types of loads and the in-rush current they create are summarized in the following chart. Type of Load In-Rush Current Resistive load Steady-state current Solenoid load 10 to 20 times the steady-state current Motor load 5 to 10 ti
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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
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Do not share the external supply voltages (the V and C terminals) with other devices (including other FieldPoint devices), unless those devices are isolated from human contact. You must connect the protective earth (PE) ground terminal on the cFP-BP-x backplane to the system safety ground. The backplane PE ground terminal has the following symbol stamped beside it: . Connect the backplane PE ground terminal to the system safety ground using 14 AWG (1.6 mm) wire with a ring lug. Use the
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Specifications The following specifications are typical for a range of –40 to 60 °C unless otherwise noted. Relay Characteristics Number of channels..........................8 Relay type .........................................1 SPST, nonlatching Maximum switching capacity (resistive load) –40 to 60 °C AC ........................................1.5 A at 250 VAC DC........................................1.5 A at 0 to 35 VDC 1 A at 55 VDC 0.4 A at 120 VDC Minimum switching load.................
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Physical Indicators ..........................................Green POWER and READY indicators, 8 green output state indicators Weight cFP-RLY-421..............................130 g (4.5 oz) Power Requirements Power from network module ............1,700 mW Isolation Voltage Maximum isolation voltage ..............250 V rms Channel-to-channel isolation............No isolation between channels Transient overvoltage........................2,300 V rms Environmental FieldPoint modules are intende
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Safety This product is designed to meet the requirements of the following standards of safety for electrical equipment for measurement, control, and laboratory use: IEC 61010-1, EN 61010-1 UL 3121-1, UL 61010C-1 CAN/CSA C22.2 No. 1010.1 For UL, hazardous location, and other safety certifications, refer to the product label or to ni.com. Electromagnetic Compatibility CE, C-Tick, and FCC Part 15 (Class A) Compliant Emissions..........................................EN 55011 Class A at 10
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Where to Go for Support For more information about setting up the FieldPoint system, refer to these National Instruments documents: FieldPoint network module user manual Other FieldPoint I/O module operating instructions FieldPoint connector block operating instructions Go to ni.com/support for the most current manuals, examples, and troubleshooting information. For telephone support in the United States, create your service request at ni.com/ask and follow the calling instructions or
