Instruction/ maintenance manual of the product FP-RLY-420 National Instruments
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FieldPoint ™ is a trademark of National Instruments Corporation. Product a nd company names mentioned herein are trad emarks or trade na mes of their resp ective companies. 321904B-01 © Copyright 1998, 1999 National Instruments Corp. All rights reserved.
FP-RLY-420 2 www.natinst.com module. The maximum number of terminal bases per bank multiplied by 1 watt is the total po wer the network module can supply . For e xample, an FP-1000 or FP-1001 can support nine terminal bases (9*1 W = 9 W). Next, refer to the specif ications section in the operating instructions for the I/O modules.
© National Instruments Corp. 3 FP-RLY-420 Field Wiring The terminal base has connections for each of th e eight relay channels and an extern al supply to po wer f ield de vices. Each relay channel of the FP-RL Y -420 has two terminals: N.O. (Normally Open) and I.
FP-RLY-420 4 www.natinst.com Figures 2a and 2b sho w examples of basic wiring connections. Figure 2. Basic Field Connection (T wo Channels Shown) Relay Output Circuit The outputs of the FP-RL Y -420 consist of Form A electromechanical relays. The po wer -up state is off (open) to ensure safe installation.
© National Instruments Corp. 5 FP-RLY-420 Figure 3 shows the diagram of one channel’ s relay output circuit. Figure 3. Relay Output Circuit The maximum switching capacity of each relay is 3 A up to 250 V A C or 35 VDC. T o switch greater DC v oltages, refer to Figure 4.
FP-RLY-420 6 www.natinst.com In addition, the FP-RL Y -420 contains its ow n internal protection MO V to preve nt e xcessi vely high voltage from being applied across the contacts.
© National Instruments Corp. 7 FP-RLY-420 Diode Circuit CR Circuits Varistor Circuit Diagram Notes Use in DC applications only . Compared to RC type, circuit delays release time (2 to 5 times v alues stated in catalog). For larger v oltages, use diode with rev erse breakdown 10 times circuit voltage and forward load ci rcuit.
FP-RLY-420 8 www.natinst.com In-Rush Current The type of load and its in -rush current characteristics, together with switching frequency , can cause contact welding. F or loads with in-rush current, measure the steady state current and in-rush current to determine the proper relay .
© National Instruments Corp. 9 FP-RLY-420 After the module has been inserted into a terminal base ( and po wer is applied), the green POWER indicator lights and the FP-RL Y -420 informs the network mod ule of its presence.
FP-RLY-420 10 www.natinst.com •D o not share the external supply voltages (V and C on the terminal base) with other de vices (including other FieldPoint de vices) unless those devices are also isolated from human contact.
© National Instruments Corp. 11 FP-RLY-420 Maximum switching frequenc y Mechanical ................... ............. . 20 operations per second Electrical..................................... 1 operation per second at maximum load Relays operate time.
Mechanical Dimensions Figure 6 sho ws the mechanical dimensions of the FP-RL Y -420 installed onto a terminal base. Dimensions are gi ven in inches [millimeters].
An important point after buying a device National Instruments FP-RLY-420 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought National Instruments FP-RLY-420 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data National Instruments FP-RLY-420 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, National Instruments FP-RLY-420 you will learn all the available features of the product, as well as information on its operation. The information that you get National Instruments FP-RLY-420 will certainly help you make a decision on the purchase.
If you already are a holder of National Instruments FP-RLY-420, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime National Instruments FP-RLY-420.
However, one of the most important roles played by the user manual is to help in solving problems with National Instruments FP-RLY-420. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device National Instruments FP-RLY-420 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
