USB 8451 no timer / counter ?

Hi all,
i´m not sure if i´m in the right topic now, but i found no answer with the search function.
I tried to generate an digital pulse using timer/counter functions with Labview 8.5 and an USB 8451, but it didn´t work.
Is it possible that the USB 8451 doesn´t support timer / counter signals?
Thanks for all your answer!

Hi AK2DM,
thanks for catching this one. I missed the important piece of information that the original poster would like to generate pulses. We have a KB-entry for this. You could also generate software-timed pulses with the 8451. The jitter (timing deviation), as you mentioned, could be a problem. The same issue arises with the 6501 I mentioned!
For generating pulse trains I would recommend a basic E or M series device such as the 6210 USB.
If you have further questions, don't hesitate to ask.
Best regards,
Peter
Peter A.
Field Sales Engineer, NI Germany

Similar Messages

Integrating an NI-USB 8451 driver and Labview Run-Time Files in an installation package of a .vi application

Hello,
I've built a .vi which uses the NI-USB 8451 device (please see http://sine.ni.com/nips/cds/view/p/lang/en/nid/202368), and I would like to create an installation package to be used on a costumer's PC, which has no Labview installed on or a driver for this device.
I would like to have this installation as a completely stand-alone setup, so that the user could take this file and run it, and have the driver to the 8451, the run-time files for the Labview application installed by themselves, and have the .exe file working on a completely "clean" PC.
How can I integrate it all in one package ?
Thanks,
Michael.

Nice hearing from you again, Ipshita
I do not call any dll's currently, but am using the driver of the USB device, NI-USB 845x, version 1.0.1
Now, I would very like to make the use of my application, by another user, with no Labview or this driver on his PC, as simple as possible.
I just thought that maybe I could create an .EXE file with some Labview created dll's, which this executable would use, and spare the need of the 845x Driver or Labview Run-Time library prior installation. I could be wrong.
What should I do ?
P.S.
Meanwhile, I've been playing with the Application Builder and tried to create an installation with the Driver and the Labview Run-Time.
It had started the compile, but stopped with the following pop-up window: "Locate the 'NI-845x Software 1.0.1' distribution. Labview needs to copy a component installed or updated by the distribution..."
(Attaching the pop-up window below)
What is it looking for and where can I find it ?
Thanks,
Michael.
Attachments:
Installation_pop-up.JPG ‏20 KB

USB 8451 waveform generator

Hi,
Can we generate a square waveform by using digital I/O lines of USB 8451 card ?

I want to generate a waveform of freq 1.25 MHz. the time between two high is 800 ns with width of high is 80 nsec.
Generating pulse train of this high frequency and precise duty cycle is not recommended using this card. Such high frequency can be generated using counter provided by E or M series card that provides STC. Software timed pulse generation that you are trying to establish are suitable only for low frequencies where jitter is not of much concern.
Post back for queries
With regards,
JK
(Certified LabVIEW Developer)
Give Kudos for Good Answers, and Mark it a solution if your problem is solved.

Using USB-8451 for accessing SMB Slave

Can i use the following example to read a SMB(System Management Bus) slave device using USB-8451 (since SMB is derived from I2C) .
Hardware Input and Output > I2C and SPI > I2C Basic > Generate I2C Read.vi
Thanks
Baburaj
SMSC
INDIA

The following is the read and write sequence examples , I want to confirm that this sequence is done by General I2C Read.vi .
Example Write sequence:
1)      Slave Address 0x58
2)      Register Address 0x00
3)      Byte count 0x03 (to write 3 bytes)
4)      Data Byte 1
5)      Data Byte 2
6)      Data Byte 3
Example Read Sequence:
1)      Slave Address 0x58
2)      Register Address 0x00
3)      Repeat start Slave address (will be 0x59)
4)      Byte Count 0x03 ( to read 3 bytes)
5)      Data Byte 1
6)      Data Byte 2
7)      Data Byte 3
Thanks
Baburaj

Why is my USB 8451 raising errors after working correctly?

I'm using a USB 8451 to tap into an existing I2C bus. This bus already has one master and three slave devices on it. Periodically I use the 8451 to read or write the registers from one of the slaves. The issue I am facing is that my application starts correctly and works for a period of time. However, eventually the 8451 will generate one of four error codes and cease working.
The error codes I'm seeing are:
301706 - Invalid device reference
301721 - Unknown status code
301740 - USB-8451 failed to seize the bus
301742 - USB-8451 is not responding
It turns out the original master on the device doesn't play perfectly on a multi-master bus. I believe error code 301740 is related to that. I don't understand why the other errors would occur after the device has been operating correctly. Any ideas?
Thanks,
Dave

Thanks for the response Andy. Unfortunately NI Spy didn't tell me anything I couldn't figure out for myself. ("Could not perform operation because of I/O error.") Maybe you can make something more out of it. I hooked it up to a usb tracer and all I can see from that is that the usb host times out after ~30 ms and resets the 8451. You can see the timeout on the Spy capture on line #121, viWaitOnEvent.
I connected the I2C lines to a decoding oscilloscope and I couldn't find any data transfers being blatently stepped on by either the embedded host or the 8451. The only thing that comes close is the 8451 sending a restart condition and taking control of the bus from the embedded host. This only happens when the host is writing a packet to a specific slave ('P'). These particular packets almost never conclude with an end condition. The host *usually* sends a restart right away. Several times I have seen where the 8451 issues its own (re)start condition and addresses the slave ("R") I am communicating with through my vi. I'm not positive this is related to the errors I have seen.
With the errors I am getting is it possible to reinitialize the 8451 on the fly without forcing the user to disconnect and reconnect it?
Attachments:
Capture.spy ‏47 KB

Usb-8451 i2c developement

Generated a simple program to talk to i2c on NSE5310 using usb-8451. I get the following error.
Error -301742 occurred at NI-845x I2C Write Read.vi:1
Possible reason(s):
NI-845x: The slave did not acknowledge an address+direction byte transmitted by the I2C master. Reasons include the incorrect address set in the I2C configuration or the incorrect use of the 7-bit address. When entering an address to access a 7-bit device, do not include the direction bit. The NI-845x Basic I2C API internally sets the direction bit to the correct value, depending on the function (write or read). If your datasheet specfies the 7-bit device address as a byte, discard the direction bit (bit 0) and right-shift the byte value by one to create the 7-bit address.
I do have pullup resistors of 1.5k on both SDA and SCL. I've attached the data sheet for the device and a sample program.
THANKS FOR YOUR TIME. Happy Holidays.............................
Attachments:
NI-8451 Testing ver2.vi ‏13 KB
NSE-5310_Datasheet_v1_0.pdf ‏1569 KB

You are providing the wrong address. As the error message says, you must provide the 7-bit address, excluding the read/write bit. . You are providing the full value of the first byte, including the read/write bit. In other words, you are doing the exact opposite of what the error message tells you to do. If you've set the user-bits to 0 then the correct address is 0x40.
Side-note: When you set a front panel numeric control to hex display you should also display the radix so that others know that it refers to "81" hex, and not "81" decimal, which are two different values.

USB 8451: Is the timeout controllable when doing a I2CREAD I2CWRITE?

Sorry if this isn't in the correct board.
I am using the NI USB-8451 to do I2C communication to talk to multiple devices. I would like to put some functionality into my program to build up a list of devices that are connected on the bus. It will attempt to communicate all 112 available addresses. I tried testing this out by connecting the USB-8451 to no device and communicating to address 10. It took about 5 seconds for the USB-8451 to timeout. So it would take a lengthy amount of time to do this to all 112 address. So my questions are:
Is there a way to shorten the length of the timeout?
Is there a better way of doing this?
Solved!
Go to Solution.

Hello,
Although the timeout value is not adjustable, I was able to query all 112 address using the script API pretty rapidly. Here is the VI I used. Let me know if it helps.
Have a great day!
Message Edited by O_Proulx on 11-05-2008 01:12 PM
O. Proulx
National Instruments
www.ni.com/support
Attachments:
Query all addess LV86.vi ‏20 KB
Query all addess LV85.vi ‏25 KB

What shall I put in the "device reference in" in the Read.vi?? for my USB-8451, where I found the name to be USB0::0x3923::0x7166::01349C20::RAW??

as title
what shall I put in the "device reference in" in the Read.vi?? for my USB-8451, where I found the name to be USB0::0x3923::0x7166::01349C20::RAW??
i put the whole name in and it keep telling me
Error -301706 occurred at NI-845x I2C Read.vi
NI-845x: The device reference is invalid. Verify that the supplied device reference contains a valid device name.
Thanks!

Chihway,
I apologize for misreading your post the first time around. Dennis is only half correct in this case. The USB-8451 is supposed to show up as a USB-RAW device in MAX, but you do not have to run the driver wizard to create an interface to it. In Measurement and Automation Explorer, select the USB-RAW device under USB Devices and create a VISA alias (I always use 8451) by typing it in the "VISA Alias on My System" box. You should then be able to use that alias for all communication. I hope this post helps a little more than the last one!
Sincerely,
Chris G in AE

USB 8451 I2C acknowledge bit problem

Hello,
I'm in the middle of developing a I2C interface for a Xilinx Vertex-5 evaluation board. This is a standard Philips I2C interface and I'm able to view the SCL and SDA lines and everything looks like it should be working but I'm not getting the acknowledge returned on the SDA line.
We have flags output on other pins and the acknowledge is working but it seem the SDA line isn't releasing the line to allow the acknowledge to go low.
I have tired the write program examples that came with 8.6 but they are for a serial PROM and I don't believe serial PROM return an acknowledge during programming. I have also tried the example from the "Using I2C with LabVIEW and the USB-8451" and even though all the clocks and data looks good at the proper pins the acknowledge bit stay high.
The Discussion Forum has a similar question about acknowledge on a "smbus_Read_Block" (11-9-06) where "newbieLBW" ask about this for a block read. I have tried that example and created it for a write but I'm still not getting a acknowledge bit to go low.
I have attached my I2C development vi that is just to prove functionality. And the write routine is in case loop 2.
Solved!
Go to Solution.
Attachments:
I2C PortCofig_3.vi ‏70 KB

Matt,
Yes we have verified that the Xilinx is getting the information it needs and it returning a acknowledge pulse on the 9th SCL clock pulse. I see this because we brought out the signal to a extra pin on the connector along with start and stop flags to make sure things inside the Xilinx were seeing the input properly. When I run this program in a debug mode and highlight the data path the only errors I received is from the 'run script' function when the 8451 tried to write the address.
Quick question for you. I had mention a discussion forum question about the acknowledge bit on a smbus which is quite like the I2C interface. In that
example the read multi-byte function starts with a create script, script clock rate,script issue start, address+write, script write, then another script issue
start, then it go on to another address+write. My question is, it seem to me that nothing happens on the I2C SDA line until your data enters the 'run script'
and I'm not seeing why they have two starts without a run. I have tried to duplicate the multi read front section to see what it does but mine doesn't seem
to run in as much as the SDA line never starts unless I have the run script in the read path. My understanding is that the 'script start and address+write are
just setup for the run script and without the run script nothing executes. Yes or No?
I want to thank you for taking the time to view this question I have. The purpose for this interface is a future chip we are designing and we are using the I2C for reading and writing control registers within the chip. I need to get the development platform working before I move onto the full interface and all the registers are 32 bits wide so I'm going to have to do all multi-byte reads and writes.
I hope I have answer some of your question and will be looking forward to any information you can pass along. I'm going to be out of the office until the 28th but I'll keep and eye on this forum from home where I'll be working on the full interface design but without the read and writes for now.
Merry Christmas and the Happiest of New Years to you and your family!
Gary Tyrna
Tahoe RF Semiconductor, Inc.

NI USB-8451 SPI clock release

Is it possible to release the SPI clock signal so it reamins high immediately after sending data on the SDO line? Currently, SCLK is held low for a significant period of time after transmission of the final data bit before it is released to a logic high state. Is there a way to configure this? Is there also a way to configure DIO signals independent of the SPI using scripting?

Hi John,
I believe you are referring to the clock polarity and phase.
Where Can I Find More Information About the SPI Clock in a USB-8451?
http://digital.ni.com/public.nsf/allkb/4FB0A184E545AC1586257609007537EF?OpenDocument
The information is found here in the NI-845x Hardware and Software Manual:
http://www.ni.com/pdf/manuals/371746e.pdf#page=26
Additionally, beyond using SPI scripting, we can use the basic SPI and basic DIO examples installed with the 845x driver in Help > Find Examples.
Joey S.
Software Product Manager
National Instruments

USB-8451 SPI interface with analog devices isensor

Does anyone has example VI using USB-8451 with analog devices isensor? I am new to SPI interface and very slowly learning how to use labview in conjunction with USB-8451 to do SPI sensor reading.
Any help would be appreciated. I'm using labview 8.5.

elpiar wrote:
It's working!
Well, I realized I made a small mistake in the example. The number of bytes in the array constant should be 4, not 2. The device is full duplex, meaning you can write and read from it at the same time. The NI-845x SPI Write Read VI returns the same number of bytes as the number of bytes that were written. Thus, with just 2 bytes you will not actually get the current value of the register. You would get the values from the previous command. See attached mod.
Now if I read the data is burst mode, will the output be automatically be arranged in an array of 8-bit length words? You mention something about send out out 8 clock burst. I'm not sure how I do this.
For burst mode you have to send out more bytes so you get clocks generated for the read to occur. The burst mode command is 3E00. That needs to be followed by 12 16-bit numbers for the device to return all the registers from SUPPLY_OUT to AUX_ADC. The actual bytes after the 3E00 are irrelevant for a write. The NI-845x SPI Write Read VI should then return 26 bytes (2 bytes that line up with the 3E00 command, followed by 2 bytes per register, for 12 registers). You can convert this into an array of U16 values and do the conversions based on which register you're actually reading. I've attached a VI to get you started. The example converts the SUPPLY_OUT register and each of the GYRO_OUT registers. You can finish the VI. Note that you should make the 14-bit to 16-bit extension a subVI so you're not duplicating code.
NOTE: As with all example code that is provided you should verify that the numbers you get are correct. We don't have the hardware, so we can't verify correct operation.
Attachments:
ADIS16400 XGYRO_OUT v2.vi ‏29 KB
ADIS16400 Burst Read Example.vi ‏36 KB

USB 8451 for I2C

Hello,
I am looking for a starting point.
My problem is I need to communicate with the PCA9555 (http://focus.ti.com/lit/ds/symlink/pca9555.pdf). I have searched the NI website and have come across a USB-8451 that seems to be the answer to my problem. However, I need to also measure current and this device seems to lack that ability.
First off, would this be the device I would want to use to communicate via I2C? The only reason I question this is because I cannot access the examples that would give me a good sense that I found what I was looking for.
Secondly, is there a device like this offered by NI that would be able to communicate via I2C and be able to measure current? Or do I have to purchase 2 separate devices?
Thirdly, is there anybody out there who has encountered the same problem (possibly with the same PCA9555)?
Thank you,
Gerardo Hernandez
Solved!
Go to Solution.

Hello,
I have a USB-8451 on my desk in use, and for ease of use in LabVIEW, you cannot beat it; some example code from one of my apps:
Here I am just transmitting an constant sequence (an initialisation sequence for my hardware) to a Slave with address 112 (actually an I2C bus all-call address for my devices).
If you want to keep things easy, I would suggest 2 seperate devices, one being a USB-8451. You can bit-bang I2C, etc at the cost of complexity and dev time.
Mark B
===If this fixes your problem, mark as solution!===

USB-8451 examples broken in LV 2012

I have a USB-8451 on order but it hasn't arrived yet. I went ahead and downloaded and installed the driver software, NI-845x 2.0. I am running LV 2012 (12.0.1f5 32-bit) and I didn't see any options for 2012 support in the installer, so I clicked the LV 2011 support and installed that. That seems to have created one LLB file, ni845x.llb.
I searched for examples using the 8451 but didnt' find any (i.e. "Help --> Find examples" in LV 2012). I searched NI support online and found SPI Execute Read of Shift Register.vi. When I open it and point to the llb file to resolve references, the VI is broken. All the sub-VIs are not executable. The errors are 1) call lib. fcn. note contains unwired or bad terminal, 2) invalid refnum class, and 3) you have connected two terminals of different types.
Why are these broken? Does it have anything to do with the USB-8451 not actually being hooked up to my computer?

Hi Vishak,
It may take some time for this to get fixed. I have resubmitted the request to have it fixed.
2.1.2 is still the latest version of the driver. For future reference, the best place to find the most recent version of our drivers is at ni.com/drivers.
Catherine B.
Applications Engineer
National Instruments

USB-8451 SPI Read/Write MOSI

I have a USB-8451 that I am using for SPI communications. The USB-8451 is the master device, and I have no problem sending and recieving data. The problem is that I cannot send what I want to with the USB-8451. When I execute a read command for 16 bit data, the USB-8451 sends 0x0300. I need to send certain commands over SPI in order to get the correct response; ie - send 0x1000, 0x2000, 0x3000, etc. I have not found a way to do this, and it is very critical that I am able to for this project to work correctly. Any suggestions?

Hello Johu,
The SPI Read Write vi has a data write input which takes in an array of bytes. If you want to ONLY read 16 bit, you have to put an array of 2 bytes which are 0. Since SPI is a full duplex protocol, it will send 0x00 0x00 and receive 16 bits at the same time.
Usually, you send a command before reading. So, you would send a total of three bytes, the first one being your command. The first byte returned would not contain any data, since your device is reading the command. The 2 last bytes would contain your data. So:
Bytes Sent         Bytes Read
CMD                           0 (or should be 0)
0                                 Data1
0                               Data2
You can download these test panels and try to using them to send your commands and read your data.
Please let me know if any of this is not clear or if you need more help with this. Have a great day.
O. Proulx
National Instruments
www.ni.com/support

Using USB-8451 device to drive two i2c busses

Is it possible to use a single USB-8451 device to drive two seperate i2c busses at the same time or do I need to get a second 8451

I believe these devices act as single bus controller and if you want to control two separate buses, get two devices. An alternative (depending on the scope of your application) would be to use an FPGA device to implement as many controllers as you require.
Hope this helps.
StuartR

USB 8451 no timer / counter ?

Similar Messages

Maybe you are looking for