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Chapter 2

Hardware Overview of the NI 78xxR

R Series Intelligent DAQ User Manual

2-20

ni.com

The SHC68-68-RDIO was designed specifically for R Series devices and is 
the NI-recommended cable for digital applications. If you are using the 
SH68-C68-S cable, however, please note the following considerations.

The SH68-C68-S shielded cable contains 34 twisted pairs of conductors. To 
maximize the digital I/O available on the NI 78

xx

R, some of the DIO lines 

are twisted with power or ground and some DIO lines are twisted with other 
DIO lines. To obtain maximum signal integrity, place edge-sensitive or 
high-frequency digital signals on the DIO lines that are paired with power 
or ground. Because the DIO lines that are twisted with other DIO lines can 
couple noise onto each other, use these lines for static signals or 
non-edge-sensitive, low-frequency digital signals. Examples of 
high-frequency or edge-sensitive signals include clock, trigger, pulse-width 
modulation (PWM), encoder, and counter signals. Examples of static 
signals or non-edge-sensitive, low-frequency signals include LEDs, 
switches, and relays. Table 2-4 summarizes these guidelines.

Table 2-4.  

DIO Signal Guidelines for the NI 78

xx

R

Device

Digital Lines

SH68-C68-S 

Shielded Cable 

Signal Pairing

Recommended Types 

of Digital Signals

NI 781

x

R

DIO<0..27>

DIO line paired 
with power 
or ground

All types—high-frequency or 
low-frequency signals, 
edge-sensitive or 
non-edge-sensitive signals

DIO<28..39>

DIO line paired 
with another 
DIO line

Static signals or 
non-edge-sensitive, 
low-frequency signals

NI 783

x

R,

NI 784

x

R,

NI 785

x

R

Connector 0, DIO<0..7>; 
Connector 1, DIO<0..27>; 
Connector 2, DIO<0..27>

DIO line paired 
with power 
or ground

All types—high-frequency or 
low-frequency signals, 
edge-sensitive or 
non-edge-sensitive signals

Connector 0, DIO<8..15>; 
Connector 1, DIO<28..39>; 
Connector 2, DIO<28..39>

DIO line paired 
with another 
DIO line

Static signals or 
non-edge-sensitive, 
low-frequency signals

Summary of Contents for NI 784xR

Page 1: ...Intelligent DAQ NI R Series Intelligent DAQ User Manual NI 781xR 783xR NI 784xR and NI 785xR Devices R Series Intelligent DAQ User Manual June 2008 370489F 01...

Page 2: ...ebanon 961 0 1 33 28 28 Malaysia 1800 887710 Mexico 01 800 010 0793 Netherlands 31 0 348 433 466 New Zealand 0800 553 322 Norway 47 0 66 90 76 60 Poland 48 22 3390150 Portugal 351 210 311 210 Russia 7...

Page 3: ...ctronic or mechanical including photocopying recording storing in an information retrieval system or translating in whole or in part without the prior written consent of National Instruments Corporati...

Page 4: ...t of Communications DOC Changes or modifications not expressly approved by NI could void the user s authority to operate the equipment under the FCC Rules Class A Federal Communications Commission Thi...

Page 5: ...4 User Defined I O Resources 1 4 Device Embedded Logic and Processing 1 4 Reconfigurable I O Architecture 1 5 Reconfigurable I O Applications 1 6 Software Development 1 6 LabVIEW FPGA Module 1 6 LabVI...

Page 6: ...ded Signal Sources NRSE Input Mode 2 15 Common Mode Signal Rejection Considerations 2 16 Analog Output 2 16 Connecting Analog Output Signals 2 17 Digital I O 2 17 Connecting Digital I O Signals 2 17 R...

Page 7: ...This icon denotes a note which alerts you to important information This icon denotes a caution which advises you of precautions to take to avoid injury data loss or a system crash When this symbol is...

Page 8: ...re and software you use for your application you could have any of several types of documentation The documentation includes the following documents Getting Started with R Series Intelligent DAQ This...

Page 9: ...s to the LabVIEW Help and other Real Time Module documents for more information as you create the real time application To access this document refer to ni com manuals In LabVIEW 8 0 or later you can...

Page 10: ...er LabVIEW contains an extensive library of VIs and example programs for use with R Series devices To access the NI Example Finder open LabVIEW and select Help Find Examples then select Hardware Input...

Page 11: ...f the device You can change the functionality of the FPGA on the R Series device in LabVIEW using the LabVIEW FPGA Module to create and download a custom virtual Table 1 1 NI 78xxR R Series Intelligen...

Page 12: ...connected between devices R Series PXI devices access the RTSI bus through the PXI trigger lines implemented on the PXI backplane Refer to the NI R Series Intelligent DAQ Specifications available at n...

Page 13: ...functions in hardware Refer to Chapter 2 Hardware Overview of the NI 78xxR for descriptions of the I O resources on the NI 78xxR Reconfigurable I O Concept R Series Intelligent DAQ devices are based...

Page 14: ...endent timed loops with separate I O resources User Defined I O Resources You can create your own custom measurements using the fixed I O resources For example one application might require an event c...

Page 15: ...ents using the LabVIEW FPGA Module The FPGA logic provides timing triggering processing and custom I O measurements Each fixed I O resource used by the application uses a small portion of the FPGA log...

Page 16: ...s of FPGA VIs Software Development You can use LabVIEW with the LabVIEW FPGA Module to program the NI 78xxR To develop real time applications that control the NI 78xxR use LabVIEW with the LabVIEW Rea...

Page 17: ...onal Instruments NI RIO RIO Device Setup Help LabVIEW Real Time Module The LabVIEW Real Time Module extends the LabVIEW development environment to deliver deterministic real time performance You can w...

Page 18: ...to the NI SCB 68 terminal block to provide higher signal integrity and noise immunity SHC68 68 RDIO NI Recommended 1 2 NI SCB 68 High performance shielded cable wired specifically for signal connectio...

Page 19: ...maged in any way If the device is damaged return it to NI for repair Do not substitute parts or modify the device except as described in this document Use the device only with the chassis modules acce...

Page 20: ...a description of installation categories Measurement Category I is for measurements performed on circuits not directly connected to the electrical distribution system referred to as MAINS3 voltage Thi...

Page 21: ...t in fixed installations distribution boards and circuit breakers Other examples are wiring including cables bus bars junction boxes switches socket outlets in the fixed installation and stationary mo...

Page 22: ...k diagram for the NI 7830R Figure 2 3 shows a block diagram for the NI 7831R 7833R 784xR 785xR Figure 2 1 NI 781xR Block Diagram Configuration Configuration Control Connector 0 DIO Connector 1 DIO Con...

Page 23: ...put Mode Mux AISENSE AIGND Calibration Mux Voltage Reference Temperature Sensor Calibration DACs 2 x4 Channels 16 Bit DAC Digital I O 16 User Configurable FPGA on RIO Devices Bus Interface Data Addres...

Page 24: ...AO channels 56 bidirectional DIO lines that you can configure individually for input or output and a Virtex II XC2V1000 FPGA AI AI PCI PXI CompactPCI Bus Input Mux Instrumentation Amplifier Input Mod...

Page 25: ...t independent 16 bit AI channels eight independent 16 bit AO channels and 96 bidirectional DIO lines that you can configure individually for input or output The NI PXI 7851R has a Virtex 5 LX30 FPGA t...

Page 26: ...uses two AI lines The positive input pin connects to the positive terminal of the onboard instrumentation amplifier The negative input pin connects to the negative input of the instrumentation amplifi...

Page 27: ...t of the instrumentation amplifier for each channel In RSE input mode the negative input of the instrumentation amplifier for each channel is internally connected to AIGND In NRSE input mode the AISEN...

Page 28: ...ive and negative inputs of the instrumentation amplifier The instrumentation amplifier converts two input signals to a signal that is the difference between the two input signals The amplifier output...

Page 29: ...ut signal varies as the source floats out of the common mode input range Ground Referenced Signal Sources A ground referenced signal source is connected to the building system ground so it is already...

Page 30: ...resistors V1 AI i AIGND i V1 AI Vg AIGND Ground loop losses Vg are added to measured signal NOT RECOMMENDED V1 AI i AI i AIGND i V1 AI i AI i AIGND i See text for information on bias resistors Signal...

Page 31: ...rence signal or return connects to the negative input of the instrumentation amplifier Use differential input connections for any channel that meets any of the following conditions The input signal is...

Page 32: ...he ground potential difference between the signal source and the NI 783xR 784xR 785xR ground shown as Vcm in Figure 2 6 In addition the instrumentation amplifier can reject common mode noise pickup in...

Page 33: ...e side of the signal to the positive input of the instrumentation amplifier and connecting the negative side of the signal to AIGND and to the negative input of the instrumentation amplifier without r...

Page 34: ...strumentation amplifier to work If the source is AC coupled capacitively coupled the instrumentation amplifier needs a resistor between the positive input and AIGND If the source has low impedance cho...

Page 35: ...785xR should not supply one In single ended input modes electrostatic and magnetic noise couples into the signal connections more than in differential input modes The coupling is the result of differ...

Page 36: ...tial difference between the NI 783xR 784xR 785xR ground and the signal ground appears as a common mode signal at both the positive and negative inputs of the instrumentation amplifier The instrumentat...

Page 37: ...com manuals for more information about input ranges Analog Output The bipolar output range of the NI 783xR 784xR 785xR AO channels is fixed at 10 V Some applications require that the AO channels powe...

Page 38: ...for either input or output When the system powers on the DIO lines are at high impedance To set another power on state you can configure the NI 78xxR to load a VI when the system powers on The VI can...

Page 39: ...ernal pull up resistor to 5 V This resistor pulls up the 3 3 V digital output from the NI 78xxR to 5 V CMOS logic levels Refer to the NI R Series Intelligent DAQ Specifications available at ni com man...

Page 40: ...f the switch shown in Figure 2 11 Digital output applications include sending TTL or LVCMOS signals and driving external devices such as the LED shown in Figure 2 11 The NI 78xxR SHC68 68 RDIO cable c...

Page 41: ...xamples of high frequency or edge sensitive signals include clock trigger pulse width modulation PWM encoder and counter signals Examples of static signals or non edge sensitive low frequency signals...

Page 42: ...the RTSI bus is connected in parallel to all the other RTSI devices on the bus only one device should drive a particular RTSI trigger line at a time For example if one NI PXI 78xxR is configured to se...

Page 43: ...enable the local bus lines on an adjacent device if the device drives anything other than 0 3 3V LVTTL signal levels on the NI PXI 781xR 783xR Enabling the lines in this way can damage the NI PXI 781...

Page 44: ...of switches on the NI PXI 783xR For normal operation SW1 is in the OFF position To prevent a VI stored in flash memory from loading to the FPGA at power up move SW1 to the ON position as shown in Figu...

Page 45: ...Chapter 2 Hardware Overview of the NI 78xxR R Series Intelligent DAQ User Manual 2 24 ni com Figure 2 13 Switch Location on the NI PCI 781xR SW1 SW2 SW3...

Page 46: ...erview of the NI 78xxR National Instruments Corporation 2 25 R Series Intelligent DAQ User Manual Figure 2 14 Switch Location on the NI PXI 781xR NI PXI 7811R Reconfigurable I O CONNECTOR 2 DIO CONNEC...

Page 47: ...Chapter 2 Hardware Overview of the NI 78xxR R Series Intelligent DAQ User Manual 2 26 ni com Figure 2 15 Switch Location on the NI PCI 783xR SW1 SW2 SW3...

Page 48: ...PXI 783xR Figure 2 17 Switch Settings Complete the following steps to prevent a VI stored in flash memory from loading to the FPGA 1 Power off and unplug the PXI CompactPCI chassis or PCI computer 2...

Page 49: ...xR 783xR is powered on with SW1 in the ON position the analog circuitry does not return properly calibrated data Move the switch to the ON position only while you are using software to reconfigure the...

Page 50: ...ce Doing so can damage the device and the computer NI is not liable for damage resulting from such a connection The power rating on most devices is 4 75 to 5 25 VDC at 1 A Refer to the NI R Series Int...

Page 51: ...ual 2 30 ni com 3 Replace the broken fuse while referring to Figure 2 18 for the fuse locations Figure 2 18 NI 784xR 785xR Replacement Fuse Location 4 Reinstall the PCI or PXI device into the computer...

Page 52: ...for signals traveling through areas with large magnetic fields or high electromagnetic interference Route signals to the device carefully Keep cabling away from noise sources The most common noise sou...

Page 53: ...ost difficult and most accurate Loading Calibration Constants The NI 783xR 784xR 785xR is factory calibrated before shipment at approximately 25 C to the levels indicated in the device specifications...

Page 54: ...re a small amount of gain error and self calibration is sufficient The flash memory on the NI 783xR 784xR 785xR stores the results of an internal calibration so the CalDACs automatically load with the...

Page 55: ...elligent DAQ User Manual To externally calibrate your device use an external reference several times more accurate than the device itself For more information on externally calibrating your NI 783xR 7...

Page 56: ...to the NI 78xxR I O connectors Figure A 1 shows the I O connector pin assignments and locations for NI PCI 7811R 7813R and NI PXI 7811R 7813R Figure A 2 shows the I O connector pin assignments and loc...

Page 57: ...12 DIO13 DIO14 DIO15 DIO16 DIO17 DIO18 DIO19 DIO20 DIO21 DIO22 DIO23 DIO24 DIO25 DIO26 DIO27 DIO29 DIO30 DIO32 DIO34 DIO36 DIO38 35 1 36 2 37 3 38 4 39 5 40 6 41 7 42 8 43 9 44 10 45 11 46 12 47 13 48...

Page 58: ...0 55 21 56 22 57 23 58 24 59 25 60 26 61 27 62 28 63 29 64 30 65 31 66 32 67 33 68 34 1 No Connect on the NI 7830R DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND...

Page 59: ...the reference point for single ended measurements in RSE configuration and the bias current return point for differential measurements All three ground references AIGND AOGND and DGND are connected to...

Page 60: ...e Input Output Protection Volts On Off Source mA at V Sink mA at V Rise Time Bias 5V DO Analog Signals NI 783xR 784xR 785xR Only AI 0 7 AI 10 G in parallelwith 100 pF 42 35 2 nA AI 0 7 AI 10 G in para...

Page 61: ...e when using 5B signal conditioning The other 26 pin header contains all the NI 783xR 784xR 785xR analog output signals You can plug this connector directly into a 5B backplane for AO signal condition...

Page 62: ...AOGND4 AO5 AO6 AOGND6 AO7 No Connect No Connect No Connect AOGND1 No Connect No Connect AOGND3 No Connect No Connect AOGND5 No Connect No Connect AOGND7 No Connect 2 4 6 8 10 12 14 16 18 20 22 24 26...

Page 63: ...the NSC68 5050 Cable 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 DIO23 DIO22 DIO21 DIO20 DIO19 DIO18 DI...

Page 64: ...Figure B 1 for the general purpose switch configuration Figure B 1 General Purpose Switch Configuration for the SCB 68 Terminal Block After configuring the SCB 68 switches you can connect the I O sig...

Page 65: ...ndard Service Program Membership This program entitles members to direct access to NI Applications Engineers via phone and email for one to one technical support as well as exclusive access to on dema...

Page 66: ...product by visiting ni com certification Calibration Certificate If your product supports calibration you can obtain the calibration certificate for your product at ni com calibration If you searched...

Page 67: ...lossary Symbol Prefix Value p pico 10 12 n nano 10 9 micro 10 6 m milli 10 3 k kilo 103 M mega 106 G giga 109 Numbers Symbols Degrees Greater than Greater than or equal to Less than Less than or equal...

Page 68: ...nalog voltage to a digital number AI Analog input AI i Analog input channel signal AIGND Analog input ground signal AISENSE Analog input sense signal AO Analog output AO i Analog output channel signal...

Page 69: ...ode signal usually expressed in decibels dB common mode voltage Any voltage present at the instrumentation amplifier inputs with respect to amplifier ground CompactPCI Refers to the core specification...

Page 70: ...to from computer memory DNL Differential nonlinearity A measure in LSB of the worst case deviation of code widths from their ideal value of 1 LSB DO Digital output E EEPROM Electrically erasable prog...

Page 71: ...aphical programming language that uses icons instead of lines of text to create programs LSB Least significant bit M m Meter max Maximum MIMO Multiple input multiple output min Minimum MIO Multifuncti...

Page 72: ...vary with respect to the measurement system ground O OUT Output pin A counter output pin where the counter can generate various TTL pulse waveforms P PCI Peripheral Component Interconnect A high perfo...

Page 73: ...e I O rms Root mean square RSE Referenced single ended mode All measurements are made with respect to a common reference measurement system or a ground Also called a grounded measurement system RTSI R...

Page 74: ...unction of the temperature TTL Transistor transistor logic two s complement Given a number x expressed in base 2 with n digits to the left of the radix point the base 2 number 2n x V V Volts VDC Volts...

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