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USER GUIDE
NI 6520/6521
Caution (NI 6521 Only)
isolation between I/O channels and the backplane, as verified by a dielectric withstand test,
5 s maximum. For more information on hazardous voltage requirements and safety
information for the NI 6521, refer to the
Contents
This document describes how to use the National Instruments 6520 and
6521 data acquisition (DAQ) devices with NI-DAQ 7.5 or later. Device
specifications can be found on
installed the DAQ device, refer to the DAQ Getting Started Guide for
installation instructions.
The NI 6520/6521 contains five Form A single-pole single-throw (SPST)
non-latching relay outputs, three Form C single-pole double-throw (SPDT)
non-latching relay outputs, and eight channel-to-channel isolated industrial
inputs. The relay's maximum switching power is 60 W/60 VA. The
maximum switching voltage for the NI 6520 is 30 Vrms/42.4 V
60 VDC. The maximum switching voltage for the NI 6521 is
150 VDC/VAC.
The NI 6520/6521 uses positive logic. A digital high energizes the relay,
and a digital low deenergizes it. In the energized state, the common (COM)
contact is connected to the normally open (NO) contact. For Form C relays
in the deenergized state, the common contact is connected to the normally
closed (NC) contact. For Form A relays in the deenergized state, the
common contact is not connected to the normally open (NO) contact. When
the board (PC) is powered off, the relays are deenergized.
This 150 V Measurement Category II module features 1,400 Vrms
Configuration .......................................................................................... 2
Functional Overview............................................................................... 3
Safety Information .................................................................................. 4
Related Documentation........................................................................... 6
Features ................................................................................................... 6
Digital Filtering................................................................................ 6
ni.com/manuals
NI 6521 Isolation Voltages
. If you have not already
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section.
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Table of Contents
Related Manuals for National Instruments NI 6520
Summary of Contents for National Instruments NI 6520
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Page 1: Table Of Contents
60 VDC. The maximum switching voltage for the NI 6521 is 150 VDC/VAC. The NI 6520/6521 uses positive logic. A digital high energizes the relay, and a digital low deenergizes it. In the energized state, the common (COM) contact is connected to the normally open (NO) contact. For Form C relays in the deenergized state, the common contact is connected to the normally closed (NC) contact. -
Page 2: Configuration
Specifications...................22 Where to Go for Support .................22 Configuration The NI 6520/6521 device is completely software configurable, so it is not necessary to set jumpers for I/O configuration. The PCI-6520/6521 is fully compliant with the PCI Local Bus Specification, Revision 2.1, and the PXI-6521 devices are fully compliant with the PXI Hardware Specification, Revision 2.1. -
Page 3: Functional Overview
The NI 6521 is designed to meet the requirements of UL/IEC 61010-1 and is UL listed. Refer to the driver software documentation for configuration instructions. After the NI 6520/6521 device and the driver software are installed, the DAQ device appears under the Devices and Interfaces branch of the MAX configuration tree. -
Page 4: Safety Information
DIO device if it is damaged in any way. If the DIO device is damaged, return it to National Instruments for repair. Do not substitute parts or modify the DIO device except as described in this document. - Page 5 Working voltage is the highest rms value of an AC or DC voltage that can occur across any particular insulation. MAINS is defined as a hazardous live electrical supply system that powers equipment. Suitably rated measuring circuits may be connected to the MAINS for measuring purposes. © National Instruments Corporation NI 6520/6521 User Guide...
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Page 6: Related Documentation
Features Digital Filtering Use the digital filter option available on the NI 6520/6521 input lines to eliminate glitches on input data. When used with change detection, filtering can also reduce the number of changes to examine and process. You can configure the digital input channels to pass through a digital filter after the photocouplers, and you can control the timing interval the filter uses. -
Page 7: Digital Filtering Example
Table 1 lists the pulse widths guaranteed to be passed and blocked. Table 1. NI 6520/6521 Digital Filter Timing Intervals Pulse Width Passed Pulse Width Blocked Filter Interval Low Pulse High Pulse Low Pulse High Pulse + 100 μs – 100 μs /2) + 100 μs... -
Page 8: Programmable Power-Up States
Figure 4. Programmable Power-Up States for Form A Relays User-configurable power-up states are useful for ensuring that the NI 6520/6521 power up in a known state. To use MAX (recommended) to program the power-up states, select the device and click the Properties button. Refer to the software... -
Page 9: Change Detection
Change Detection You can program the NI 6520/6521 device to send an interrupt when a change occurs on any input line. The DIO device can monitor changes on selected input lines or on all input lines. It can monitor for rising edges (0 to 1), falling edges (1 to 0), or both. -
Page 10: Watchdog Timer
NI 6520/6521 while power is provided to the PC/board. When the watchdog timer is enabled, if the NI 6520/6521 does not receive a watchdog reset software command within the time specified for the... -
Page 11: Pin Assignments
Relay Signal Connection Example section. The input lines on the NI 6520/6521 consist of input photocouplers, which react to a voltage differential rather than only to a voltage increase. For an input channel, if the voltage difference between two input lines is greater than logic threshold, the reading on the digital line will be logic high. -
Page 12: Signal Descriptions
P0.4– P0.7+ P0.6+ P0.7– P0.6– Figure 5. NI 6520/6521 Pin Assignments For more information on signals on the NI 6520/6521, refer to the Signal Descriptions section. Signal Descriptions Table 3. NI 6520/6521 Signal Descriptions Signal Name Description 1, 20, 4, 23, 7, 25, 9, 27 NO.<7..0>... -
Page 13: Optically Isolated Differential Inputs
+30 VDC, for signals connected between P0.X+ to P0.X–, where X is line <0..7>. Sensing DC Voltages The NI 6520/6521 can sense DC signals from 11 V to DC power supply levels up to 30 V. Input voltages between –4 V to +4 V produce a logic low. Input voltages between –30 V to –11 V or between +11 V to +30 V produce a logic high. -
Page 14: Input Signal Connection Example
Figure 6 and Figure 7 show signal connections for a supply connected to an isolated input. The power supply can be any DC voltage within the NI 6520/6521 device range. Refer to the device specifications for information about voltage ranges. -
Page 15: Mechanical Relays
(break-before-make). Non-Latching Relays The relays on the NI 6520/6521 are non-latching. A non-latching relay has an initial position of normally closed (NC). This position is maintained by the force of a spring or permanent magnet while no current flows. The normally open (NO) contact is closed by the force of a magnetic field while current flows through the coil. -
Page 16: Power-On And Power-Off Conditions
Programmable Power-Up States section and the Non-Latching Relays section. Relay Signal Connection Example To connect to the NI 6520/6521 signals for Form C relays, connect NC, NO, and COM, as shown in Figure 10. P1.X COM P1.X NC P1.X NO... -
Page 17: Power Connections
To connect to the NI 6520/6521 signals for Form A relays, connect NO and COM, as shown in Figure 11. P1.X COM P1.X NO Power Load Figure 11. Relay Signal Connection Example for Form A Relays Power Connections Isolation Circuitry Input Isolation Circuitry The optocouplers optically isolate the NI 6520/6521 digital input channels. -
Page 18: Ni 6521 Isolation Voltages
The NI 6521 must be used with special keyed cables and accessories. Refer to the 37-Pin High-Voltage Accessory Safety Kit Installation Guide shipped with your device and the NI 6520 Accessory Options section for more information. The PCI-6521 must be installed in a PC that adequately grounds the front panel bracket to the chassis of the PC. - Page 19 Figure 13 shows a MOV installed across an inductive load for AC loads. Flyback Diode NI 6520/6521 CHAN – Figure 12. Contact Protection for DC Inductive Loads NI 6520/6521 CHAN Inductive Load Figure 13. Contact Protection for AC Inductive Loads © National Instruments Corporation NI 6520/6521 User Guide...
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Page 20: Cables And Accessories
TB-37F-37SC 37-Pin Solder Cup Terminals, Shell with Strain Relief—part number 779184-01 For more information about optional equipment available from National Instruments, refer to the National Instruments catalog or visit the National Instruments Web site at ni.com NI 6520/6521 User Guide... -
Page 21: Pci-6521 Accessory Options
SH37F-37M-1 37-Pin Female-to-Male Shielded I/O Cable, 1 m—part number 778621-01 Or choose the following direct connect custom connectivity option: – TB-37F-37CP 37-Pin Crimp & Poke Terminals, Shell with Strain Relief—part number 779185-01 © National Instruments Corporation NI 6520/6521 User Guide... -
Page 22: Specifications
Refer to the NI 6520 Specifications, available at , for ni.com/manuals more detailed information about the NI 6520 device. Refer to the NI 6521 Specifications, shipped with your device and available at ni.com/ , for more detailed information about the NI 6521 device. - Page 23 Instruments trademarks. Other product and company names mentioned herein are trademarks or trade names of their respective companies. For patents covering National Instruments products, refer to the appropriate location: Help»Patents in your software, the patents.txt file on your CD, or ni.com/patents.