Pull-up resistor R Series

Hi
I am using NI PCI 7833R. I would like to raise the voltage from 3V to 5V. I have configured one DIO pin as an output and I have connected to it one resistor equal to 10kOhms. One end of the resistor is connected to the output of the PCI board and the other end of the resistor is connected to an external power supply (5V). I have expected to achieve 5V on the output but without success. Could you please give me an advise. I would like to generate a sqare signal from 0 to 5V.

Cool. I just checked out the specifications and it states that this card is capable of generating 5V signals, so you've probably found a pin capable of doing it!
Can you show me the datasheet of the motor you're using?
I assume you're using a stepper motor. You do need to supply a lot more current to it than is capable from the driving pin of the PCI card to get a motor turning. At a push you could probably drive a very small hobby motor directly from a power rail, but that's all. Motors require current proportionally to their size; larger motors require more current. Stepper motors the size of an apple for example require about 1A to get turning. If you check out the specification of the card, you'll see that there's no way of driving that kind of current directly from an output pin.
To increase the drive capacity, the motor needs to be connected to a Bridge Circuit, or a stage interface for the motor. If you look up the motor specifications you should see some examples on how to construct an appropriate interface with it.
Alex Thomas, University of Manchester School of EEE LabVIEW Ambassador (CLAD)

Similar Messages

Input port, Pin 10 to pin 13, Do they have internal pull up resistors?

Do the inport pins have internal pull up resistors on the computer side?

It looks like the IEEE standard does warrant pull-up for these pins. But it may depend on what chip is used on the mobo of your PC. Have a look here, it was my first Google search match out of 612 using "IEEE 1284" + "port" + "pull-up".
http://www.calmicro.com/products/data/pdf/ap_203.pdf
If you can access the Vcc pin and with all power to the PC off, you should be able to ohm out 1-4.7Kohm of resistance consitently between the Vcc pin and each pin in the range 10 to 13.
May I suggest further posts include more information on the specifics of the question.
Hope this helps!
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"It’s the questions that drive us.”
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Disable PXI-6224 pull down resistors

Can the pull down resistors on the digital inputs of the PXi-6224 be disabled?

Not as far as I know. You shouldn't just let DIO float as that could damage parts when in the transition area. That's why the pull downs are there. Would you rather have pull ups? You can put in something like a 1k pull up resistor and that would swamp out the pull down resistors. According to the spec, the pull down resistors are 20k minimum, 50k typical.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

660x weak pull-down resistor schematic

The 660x spec sheet mentions that the Power-on state has a Input (high-Z) with weak pull-downs, but I cannot find a schematic with this weak pull-down resistor value.
I want to measure a clock signal on my DUT without loading or distorting the signal, so I plan to use a buffer. I'm concerned about the required drive current to overcome the built-in pull down resistors and the resulting threshold requirements of my PXI-6608 counter.
If anyone has a link to recommended buffers, level shifters, or a knowledge base article with an example circuit, it would be much appreciated!!
http://www.ni.com/pdf/manuals/372141b.pdf
Solved!
Go to Solution.

I am attempting to measure a 16.384 MHz clock driven by a Fairchild Semiconductor NC7SV126 buffer to a microcontroller.
http://www.fairchildsemi.com/ds/NC/NC7SV126.pdf
After some research, I like the TI SN74LVC1T45 (420 Mbps max), single bit dual supply transceiver. This offers 2 supply rails, but it does not offer an enable pin. I may have to add a relay to connect VCCB to GND so that the signal from the test fixture to the PXI-6608 is not always on. Connecting the VCC to GND switches the input/output ports to a high impedance state which will not load the DUT circuit and should protect the DUT and buffer from ESD damage.
http://www.ti.com/product/sn74lvc1t45
The DUT supplies a 3.3V rail for the NC7SV126 buffer which could be connected to the VCCA of the SN74LVC1T45, and the 5V rail from the PXI-6608 could be connected to the VCCB of the NC7SV126 buffer.
quick specs:
NC7SV126 at 3.3V VCC = VOH 2.2V min, VOL 0.55V max
SN74LVC1T45 at 3.3V VCCA = VIH 2.0V min, VIL 0.8V max
SN74LVC1T45 at 5.0V VCCB = VOH 3.8V min, VOL 0.55V max
PXI-6608 = VIH 2.0V min, VIL 0.8V max
Also, here's a good application note from TI:
Selecting the Right Level-Translation Solution
http://www.ti.com/lit/an/scea035a/scea035a.pdf

Digital device to use to measure 3.3V logic with 5k pull-up and 10k series resistance

I have a digital instrument with the setup that is shown below. I wish to measure the logic state of the line with a National Instruments device. Which one do you recommend?
Trials and Failures: I tried using the usb-6501 but because of the 5V and 5k ohm pull-up on the insides of this device, I was getting bad readings and was told by my peers that this was the wrong instrument to use. I also tried using the digital pins on the usb-8451 and received the incorrect measurements. I need to figure out why the usb-8451 seemed to have the input pins floating when the logic level I provided as an input was a LOW.
The figure below is a representation of my signal source:

Denn2 wrote:
Thank you for the response. Since my DUT is already assembled, it is a little late to add chips. However, a coworker suggested adding a 0 ohm jumper on top fo the 10k resistor. I will see if this works and provide an update.
I was recommending adding the chip to your test circuitry, not the DUT.
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Series resistors for digital IO?

Hello,
I have PXI-6508 digital io cards in my PXI chassis. The max output current for the digital lines is about 4mA. I had a problem where I had a digital port I was using as outputs blow out, presumably because it was outputting too much current.
I plan on putting resistors in series with all of the outputs from my DIO card to limit the current.
Are there any products on the market that do this? For example I was hoping that maybe there is an adapter that plugs onto the DIO card and places resistors in series with each line, then I could connect to the adapter.
Anybody else have current limiting methods they use. I don't want to have to put a bunch of resistor networks in each fixture I build.
Thanks
Mike

Hey Mike,
I am not aware of any pre-built connectors that would take care of this for us. However, I would like to make some clarifications (sorry if this is unneed information). First off, resistors can act as current limiters, but realize that the output voltage of the system may no longer be TTL. There will be a voltage drop across the resistors. A system set up like this could possibly work with one 6508 and not another, their output voltage can vary from 2.4 to 5 volts.
It sounds to me like you are trying to drive something with too low of an impedance. While using a resistor may work in this situation, it is usually best to use a device that can drive enough current, or use signal conditioning that can provide enough current. The 6508 should not be
used to drive anything less then 2.4V/4mA, or 600 Ohms. The 6509 has the ability to drive 2.4V/24mA, or 100 Ohms. The 6514/15 can drive even more current.
Lastly, if we are just trying to protect the circuitry from an unlikely case, I would suggest using a fuse.
Best regards,
Justin T.

Is there anyway to disable the pullup resistors to 5V on 6070E

The internal pullup resistors on the inputs of the 6070E card are interferring with the circuit of my DUT (the DUT has pulldown resistors).

The E Series boards (6070E) use the DAQ-STC chip for the 8 digital lines of port 0, which consists of +5 V connected to a 50 kOhm pull-up resistor. This is hard wired within the board and cannot be disabled.
If you cannot work around this with your external circuitry, you may need to get a different board with user-defined pull-up/down capability.
PC-DIO-24/96 - User-defined* 100 kOhm
NI-6013/6014 - Pull-down 1.5 kOhm
NI-6533/6534 - User-defined* 100 kOhm
AT-MIO-16D - Pull-up 100 kOhm
PC-LPM-16 - Pull-up 10 kOhm
DAQCard-700 - Pull-up 10 kOhm
E-Series - Pull-up** 50 kOhm***
The DIO-24/96 family allows jumper-selectable pull-up/pull-down configuration. The NI-6533/6534 family of devices similarly allows the
user to configure pulled up or pulled down DIO via the DPULL pin. See your user manual for more information.
**Digital lines 6 and 7 on the AT-MIO-16XE-50 also have pull-down resistors of 50 kOhms.
***The extended digital lines on the 6025E, AT-MIO-16E-10 and AT-MIO-16DE-10 have 100 kOhm pull-up resistors

Pull-Up DIO Lines to 5V

Hello, I'm using the NI PCIe FPGA 7852R card. When configured for output the DIO lines go from low, zero volts, to high, 3.3V. My application requires going from 0 to 5V. The manual for this card says an external pull-up resistor can be used to achieve 5V output from the card. I'm not sure how this is done, can any one recommend how to do this? Or, can anyone point me to documentation that details how to do this?
Thanks,
Ed

All kidding aside, here's a more detailed link then my original one if you want to know more about the workings of a pullup/pulldown resistor
CLA, LabVIEW Versions 2010-2013

PXI 7833R pull up

I am using Labview FPGA and PXI 7833R card.
the PXI 7833R card has normal output swing from 0 to 3.3v. If I wanna drive a 5V CMOS logic . The manual says I can use a pull up resistor.
My question is that when I use the pull up resistor, should I set up the digital output through the FPGA software, or I just use a pull up resistor without doing anything else?
this picture is how the manual does.
Attachments:
c.jpg ‏32 KB

Hi There:
Thank you for your question. I am not sure I have understood your question correctly so if this post does not answer your question please let me know so that I can research further.
Basically all the pull up resistor is taking the output of 3.3V and pulling it up to 5V. The board outputs 3.3V when a high logic is seen at the terminal. The logic that you send out to the terminal is determined by the code in your FPGA vi. So to answer the question, you will have to connect a pull up resistor and set the digital outputs using the FPGA software which in this case is LabVIEW FPGA.
I hope that helps.
Best Regards,
Jaideep

Alphanumeric Display Problems

I'm trying to use a standard 15-Segment Alphanumeric Display, combined with a series of Karnaugh-Simplified generic gates in order to display a series of characters when 3 switches are combined in a binary code. However, once the display changes characters, the previous one blinks on and off rapidly. This doesn't happen when I use just SPST switches on the LED pins, only when I use SPDT, with one terminal to ground, so naturally I assumed it was because the LEDs were being grounded, some sort of simulation bug...so I tried using transistors to cut the current without grounding it, which worked in a small test, but not on the large circut...How can I fix this problem? Thanks.
Here's the circuit, in its original form.
Attachments:
circuit2.PNG ‏25 KB

I have been wrestling with this for a while and the conclusion that I come to is that the Display is someway causing this. I have tried everything I can think of which includes pull down resistors across each led, a resistor tied from each display ground and also series resistors in line with the LED segments and nothing seems to work. I have even replaced the switches and that didn't work either.
It appears to me that the model for the Display is not blanking it when a transiston occurs and therefore the previous information is still visible. With this said, I was able to do one thing and that was to make my switch changes and then restart the simulation. This way the display blanks and the switch information is displayed correctly. I know this isn't the way it should be, but it is all I could come up with to make it do what we both wanted it to do.
I am sorry if this doesn't help, but I have no other ideas at this point to explore.
Kittmaster's Component Database
http://ni.kittmaster.com
Have a Nice Day

Turbine flow meter conversion

Hi,
Apologies for the query but this software is all new to me . I have a 9188 cDaq 8 way chassis containing several modules including 2 off 9401 counter modules, I am running signal express version 6.0.0.
My issue is I have 3 miniature turbine flow meters (Gems units FT-110 series) which are giving out 5V square waves at varying pulse widths dependant upon what the flow is. I've scoped the input to my 9401 and the signals look good so am assuming it's my signal express configuring that is causing the problem,
I've wired the +ve and gnd outputs of the flowmeters to DIO0 +Com, DIO1 + Com and DIO3 + Com on one of my 9401 cards.
I can see the pulse count increment on measurement & automation explorer when I run the test panel for that module and look at the edge counts so my system can see the pulse trains coming in.
When configuring signal express I need this to read in l/min, 58-575Hz should equate to 0.5-5 l/min, however I cannot seem to convert the pulses to l/min.
If I select DAQmx acquire>counter input>frequency it gives me the option of custom scaling but every time I run it I get the DAQ assistant error flagging up. I tried numerous timing settings with no luck. The only time I've got this to count succesfully is using counter input>edge count but I'm stuck on how to convert this into l/min as there is no scaling function (that I'm aware of!)
Any help appreciated.
Solved!
Go to Solution.

I think he's referring to l/min as Liters per minute, and i'm assuming the Freq to Flow are the values that corrolate to the scaling.
If that's the case; Carl, it sounds to me you need to setup a custom scale. You can do this in the Channel Settings tab in the DAQmxAcquire step. Under custom scaling select Create New and select Map Range Scale. You min/max Freq should equal your min/max flow rate.
I've attached some screenshots for reference.
Let us know if we're on the right track, otherwise we may need more info; I.E. .seproj file and a bit more info on the flow meter (connection type, output signal, etc).
Also, a brief glance at the documentation on that flow meter recommends the use of a pull-up resistor. May want to look at that as well.
SCXI- 1000 Chassis w/ 1346 adapter
PCI 6281 DAQ card
SCXI- 1520 Bridge Board w/ 1314 Terminal Block (x2)
SCXI- 1180 Feedthrough Panel w/ 1302 Block
Signal Express 2014.
Win7 Enterprise
Attachments:
freq_lpm.JPG ‏82 KB
dmxA.JPG ‏100 KB

Es posible recuperar el celular si el ladrón actualizo el ios a la última versión.

Hola será que alguno me podrá ayudar con una duda que tengo.
Si se perdió el celular y tenia activado el buscar con Ios 5.0.3 pero no aparece, si quizás el ladrón le instala ios 7 cabe la posibilidad de encontrarlo por el imal o definitivamente no tengo nada que hacer.
Hello is that one can help me with a question I have. If the phone is lost and had enabled search with Ios 5.0.3 but does not appear if the thief may install ios 7 goes the possibilities to find the imal or definitely have nothing to do.

If I understand the translation correctly, you are using an open collector NPN output from a flow sensor, and want to count the pulses. In this case, use a pull-up resistor to the +5 volt line from the open collector, and then connect the junction of the open collector and the resistor to the counter input of your DAQ card. This will allow you to read the output of your sensor as a voltage pulse.
good luck,
Dave

How to isolate USB-8451, I2C/SPI Interface

How can I protect the SCL & SDA lines on a USB-8451 from overvoltage? The User Guide says:
Caution Take special care with respect to the I2C SDA and SCL lines. To allow for external
pull-ups, the circuit protection has been removed. Do not exceed the specified voltages for
these signals.
I've had several instances where my UUT applied 28 volts to one/both of these lines and destroyed my I2C interface. What can I do to protect these lines?
Jim
Jim
You're entirely bonkers. But I'll tell you a secret. All the best people are. ~ Alice

There are several ways to this. I often use this simple circuit is based on zener diodes and the basic idea is quite similar to some commercial circuits also. The zener diode react quite fast to the surges. Zener diodes also have Low capacitance, so they are suited for high speed data lines. Unfortunately the surge capacity of those zener diodes is not very high, so that they can't handle the large spikes by themselves. That's why I have added 10 ohm resistors in series with data line before the zener diodes. This resistor limits the surge current to safer value for zener diode. The resistor must be always be between the data line and zener diode, so you must plug this circuit in the way where the computer goes to the connector on the right and the data line to the connector on the left. It is possible to make this circuit "bidirectional" just by adding also resistors to the computer side of the zener diodes, but this increased the series resistance in the data line.
As mentioned there are more advanced circuits. Like active circuits. As an example the ADG467BR. Another option is Zener Transient voltage suppressors like the P6KE11CA. The P6KE11CA is bipolar so you only need 1 diode. But for a low voltage system like yours the zener solution may work fine. Remember to select a zener which can handle the current. If you 28 volt and use a 10 ohm resistor the current will not be higher than 28/10 ampere as a thumb rule. Probably lower.
Message Edited by t06afre on 01-23-2009 03:41 PM
Besides which, my opinion is that Express VIs Carthage must be destroyed deleted
(Sorry no Labview "brag list" so far)
Attachments:
sample.PNG ‏2 KB

Obtaining a TTL input signal via DIO lines of 7334

Hi
How can I obtain a TTl input signal from a source via the DIO lines of the 7334 .
Thanks
Mal

I do not quite understand your question.
If you want to know what kind of signal a DIO line will detect properly: the signal has to be less than 0.8V to detect a low state and more than 2.0V to detect a high state. This is compatible with outputs of all TTL logic circuits.
If you have some other circuitry (source) with different specifications for the digital signal you can simply connect a switching transistor in open collector circuit. The DIO lines have pull-up resistors, and when the transistor is switched the DIO input will be tied to less than 0.8V (low level).
Anyhow, if the high output level of your source is more than 5V (there are many control systems with 24V output level) it is better to use galvanic isolation to avoid damage of the motor controller. You can use a relay, or better an opto-isolator. You have to design the series resistor of the opto-isolator such that the input gets proper current to drive the LED (usually 10mA will be sufficient for most optocouplers). If the opto-isolator has an open collector output configuration it can be connected directly to the 7344 DIO line.
Of course you always have to provide a common GND connection between the 7344 board and your signal source (or the open-collector transistor in case you use this configuration or an opto-isolator).

FPGA power up state

Hi,
How can I set the powerup state for 7811R card.
I tried by running a initialization bitfile before running my application. It sets the default states, but when I run any other bitfile, the states are again going to High Impedance. I have used 'Close' option instead of 'Close and reset' in the host code.
For Ex: First I run the initialization Bitfile_1, in which I have made the state of DIO0 to 10 as FALSE.
Now, I run Bitfile_2, in which I am changing the states of the DIO12. But on doing so, the state of DIO0 to 10 are again going back to High impedance.
In both the host VIs, I have used ' Abort and Close' option instead of 'Close and reset'. The host code is attached.
How can I restrict the DIOs from going back to high impedance state if not in use???

How did you measure the voltage on the I/O lines when they are supposed to be in HiZ mode? If you do this with a DVM, you will probably get some reading different from 0V (or whatever your DVM shows when the circuit is supposed to be open), since even in HiZ mode there is a certain amount of leakage current which will be sufficient to feed the high impedance input of a DVM. (In a special application I trigger a thyristor with a TTL output and noticed false triggering when the TTL circuit was in HiZ mode - the leakage current was sufficient to trigger the thyristor gate which needs 20 uA or so to trigger.)
Also, if you connect any TTL inputs to an output which is supposed to be in the HiZ state for some time, be aware that the input m
ay float in an undefined area, since TTL inputs always have to be connected to an output with a valid (high or low) state, or to the supply rail via a pull up resistor.
To avoid the (possible) problem with leakage current in HiZ mode you can connect a resistor between the HiZ output and ground which will 'short' the leakage current. I would suggest a resistor of 4K7 or so.
To avoid any problems with non-powered circuits connected to a 5V output you can use a protection circuit consisting of a current limiting resistor in series with the input (which should not exceed 220R when using TTL or LS-TTL circuits) and a (Schottky) diode between the input (after the resistor) and the Vcc rail. A similar technique is used as protection circuit on the I/O lines of the 7344.

Pull-up resistor R Series

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