Fpga serial communication

hello,
i am using Crio and i am having a problem in serial communication even i flowed the exact steps from the exampls i always recive the same error which is "poly VI visa configure serial port: bad linkage to sub vi" is it a visa settup issue?? knowing that when i run NI MAX it indicates that there is a visa error under the peripheric and interfaces of my Crio.
thax in advance.

Can you show the code? With that error I would expect one or more broken wirtes.
Mike...
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Handling multichannel serial communication on FPGA

NI recently released cRIO modules for serial communication on RS232 and RS485/422. We need multiple RS232 channels for our RIO systems and previously the solution would have been to use a serial port server and then communicate with that using raw TCP/IP. Having the serial communication handled by RIO modules seems a bit more elegant though so I'm looking into using the RS232 module NI9870 instead.
NI has supplied an example on how to use the 9870 - a serial loopback on port 0. I've successfully modified this to be a general driver for a selectable port (added port selection and initialization), however I really need to code a solution that handles ALL the 4 channels in parallell. I'm not sure what would be the best way to do that though. DMA FIFOs seem to be the best option for host-target communication, however in this case there are 4 channels....and I may have multiple modules so at most it could be that I need to handle as much as 32 ports. The example uses interrupts for synchronization....which off course is also a limited resource. All in all I'll probably figure out a way to do this, however if anyone else have done something similar already it would be great to hear your views on this.
Coming from the Windows-programming world (this is the first FPGA work I've done) I was also hoping to make this driver as general as possible, maybe even be able to write a wrapper containing both VISA based serial functions and the FPGA host code. That way it could be transparent how the port is accessed.
This would require 1 code that would be able to handle a variety of module configurations (well, 1 to 8 NI9870 modules in the chassis), however that does not seem to be feasible(?). When you read or write to a port you cannot just refer loosely to it with a number e.g. - the read and writes are referenced to a specific port...this means that unlike in a Windows application where you can let the user just configure that he wants to use COM port num XX and the serial functions will accept that number regardless of whether the port exists or not (returning an error if it does not exist or is in use) - the FPGA code has to have all the items it will call pre-defined. If the chassis can have 16 ports on 4 9870 modules it does not seem possible to use the same FPGA code if the chassis currently only has 1 module...Is this the reality, or is it possible to create a more flexible solution?
If it turns out that the FPGA has to be reprogrammed if another serial module is added (or one is removed) it would seem much better to drop the modules and use a port server and tcp/ip instead...that way using new ports will only be a question of configuration (IP and port), not reprogramming...That may not be possible always (if you need the compact size and roughness only a single RIO chassis would offer), but in our case it is - it' just not as elegant hardware-wise.
MTO

Well, the multichannel experiment only wrote data, it did not read...(see attached VIs) however the concept can be used in both directions: Add a header to the FIFO data where the header tells the recipient what port the data is going to or comes from...Then use e.g. a state machine to read the FIFO, split the header and data, and route the data to the loop handling the port.
If you are going to read data you will get into one of the downsides to this namely that you will need to have a central communications manager that reads the incoming data and distributes it to the requesting VI. This way you can have more parallell access to both read and write, however the reads will have to be routed through this handler. How big a performance gain this would give is unknown though. You still only have one DMA FIFO for each direction so there is a limit to how parallell things can get, but logically this might get you closer than the NI example...
MTO
Attachments:
9870 MultichannelIO Experiment.zip ‏1002 KB

How to send data using serial Communication

I want to make serial communication using RXTXcomm.jar file.I was written the code.From this I got the list of serial ports avilable on pc but then after when I was tring to send command to machine which is attached to port it didn't gave any reply.
Tell me that how to send command to port?

This is how I do it:// open port, get ownership
SerialPort serialPort= (SerialPort)portId.open(APPLICATIONNAME, timeout);
// no framing and no threshold
serialPort.disableReceiveFraming();
serialPort.disableReceiveThreshold();
// communication speed, parity, stopbits and databits
serialPort.setSerialPortParams(BAUDRATE, SerialPort.DATABITS_8,
SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
// no handshaking or other flow control
serialPort.setFlowControlMode(SerialPort.FLOWCONTROL_NONE);
// timer on any read of the serial port
serialPort.enableReceiveTimeout(TIMEOUT);
// open streams for reading and writing
InputStream is= serialPort.getInputStream();
OutputStream os= serialPort.getOutputStream();... then you use the 'os' stream for writing and the 'is' stream for reading.
kind regards,
Jos

How do i open a new window? serial communication problem

I am trying to make a serial communication interface, with changeable settings,
but i wanted it to be that the settings to be openend in a new window, how am i able to do that.
I tried to make a separate subvi, but unable to do that, here is my explanation in images and the vi files.
-Just a student-
Attachments:
LVTerm.vi ‏50 KB

Hello Nandha,
SubVI's can be created by selecting the part that you want in the subVI and than select "create subVI" from the "Edit" menu.
Or cut the selected part and open a new VI and paste in the code. Then you have to connect all the controls and indicators to your connector pane. To do this right click the icon in the upper right corner and "Show connector". Select a pattern that has enough connectors, my personal favorite is the 4x4x4. Select the wire tool and select a connector and then the control or indicator you want to connect. Try to keep controls to the left and indicator to the right.
Now you have to figure out when you want to show the settings window. Is it necessary that the communication goes on during manipulation of the settings?
Kind regards,
André
Regards,
André
Using whatever version of LV the customer requires. (LV5.1-LV2012) (www.carya.nl)

Changing the name of serial communication example in lab windows. Urgent help required

I am using the example of getting data from rs 232 in lab windows. I want to use this in my final year project that's why I want to change its name that appears as "serial communication example" how can I change its name and how can I make its exe file that will run on any system even without lab windows.
How can I modify this example to save the data. I am very new to lab windows, I was using hyper terminal previously.

I am not informed about the file format that hyperterminal uses. However, CVI allows wiring to files. To get a list of functions that deal with file handling, press <Ctrl-Shift-p> to get the "Find Function Panel" dialog. Type in "file" and press the "Find" button. This will open a list of funtions that contain "file" in their name.

Problem download: Java serial communication

Hi,
I need to work with Java serial communication api for Windows.
As mentioned on SUN site, downloaded the following:
1) comm2.0.3.zip, &
2) rxtx-2.0-7pre1-i386-pc-mingw32.zip
Extracting, unable to see win32com.dll & javax.comm.properties
Can you help me?
Thanks,
Priya

Hi priya
There is problem in your downloaded s/w
Download commAPI once again then try
Read the readme file and follow the instruction

VISA Read function Read buffer problem in serial communication

Hi, I use VISA write and read function in serial communication app, the device continuously sends 0x00 if it is not receive a request from Labview program running on PC.
And the request sent by labview is programmable. I met a weird problem, each time the request changes, the VISA read buffer output port still shows the last request firstly, from second time, shows the right request.
It works like: Req code: ... 50, 51,51,51,50....; VISA Read buffer: ...50, 50, 51, 51, 51, 51, 50....
Please refer to the program.
Attachments:
readOne_test.vi ‏21 KB

How are you running this? You don't have a while loop around it. Is it part of a larger VI? Please don't tell me you are using the run continuously button.
You don't have any wait statement between you VISA Write and your bytes at port. So it is very likely the receive buffer is still empty since you didn't give your VI time to wait for the device to turn around and give a reply. If you read 0 bytes, your VISA read string will be empty. How does your decoder subVI (which you didn't include) handle an empty string?

To read 512 bytes using serial communication

I want to read 512 bytes of data using rs 232 with the timeout of 30ms. I am using "Serial read with timeout -Palm.vi". Is there a limitation of the number of bytes I can specify to this VI?
Thanks!!
Attachments:
Serial_Read_with_Timeout--Palm.vi ‏63 KB

Hi software enigineer,
It is not possible to transfer 512 bytes per 30 ms here. To do this would require a baud rate of 136533 (512*8/.03) and the maximum possible baud rate is 115000. The recommend baud rate for a serial transfer is 9600, which would mean transferring at most 36 bytes if the timeout is kept at 30ms. Moreover, there is usually some overhead involved in serial communication, and I would recommend sending a little less than the maximum 36 bytes every time too.
On another note, I noticed that in your block diagram, you are using the Bytes at Serial Port vi. Definitely use the output of this vi to determine how many bytes to read at a time and read the bytes as they become available in the serial buffer rather than reading in a large buffer
all at once. Continuously read and append the output until there are no more bytes to be read or until the termination character is read. This will avoid any lost data transmission due to overflow.
Good luck with your program!
Kileen Cheng
Applications Engineer
National Instruments

User-specified DAQ interruptions, instrument control through serial communication

I'm working on an instrument control program, and I've run into a structural problem that I cannot figure out.
The instrument in question is effectively a thermostat.
The program has two functions:
1.) Background sampling to record temperature in a log over time.
2.) Adjust temperature according to user input
The issue is that the instrument uses EIA-232 serial communication to talk to the PC.
This prohibits simultaneous execution. Attempting to send a command while the program is taking a sample will result in serial blockage errors.
So the program must interrupt background sampling until the specified command has been completed.
I can't figure out how to do this.
My best idea was to create a manual pause control. If the user wants to adjust the temperature, he hits a switch to pause the sampling, sends the appropriate command, then hits the switch again to reinitiate sampling. This method will suffice, but is not ideal.
Beyond that, I really have no idea how to prevent the two functions from running into each other.
Help structuring this program would be greatly appreciated,
Thank you

Look into Semaphores (icons with traffic light glyphs)
Set up a Semaphore resource to the COM port that is wired to two parallel structures.
One structure would do the background polling, the other would handle setting changes.
Prior to background poll, lock the resource, then unlock it after the poll. Likewise for the setting change command.
When a resource is locked, the other process cannot access it until it is unlocked. Be sure to dispose of the Semaphore when ending the program.
-AK2DM
~~~~~~~~~~~~~~~~~~~~~~~~~~
"It’s the questions that drive us.”
~~~~~~~~~~~~~~~~~~~~~~~~~~
Attachments:
SempahoreExample.jpg ‏256 KB

How to make Serial Communication in windows

Hello, I want to do serial communication using windows platform.Sun provides javax.comm package for solaris & unix but there is no any provision for windows platform.Can I use it in Windows Platform.?

http://forum.java.sun.com/thread.jspa?forumID=31&threadID=698876

Serial communication to read single character

Hi! List,
I want to read single character using serial communication(see the attached VI).
The initialization of the serial port is taken care.
TIA
Attachments:
Serial_comm[2_read_single_character].vi ‏42 KB

I'm not sure I can understand you. If you want to read just one single character why can't you do so by just passing 1 to the Serial Read function as the number of bytes to read?
The diagram of above VI doesn't make to much sense to me I have to admit.
Rolf K
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

Serial communication error

hello,
when i try to run my application(serial communication simple data transfer using loop back), labview evaluaton 8.6 showing the erron as attached.I dont understand what went wrong, it was working fine earlier.
Thanks,
hari
Solved!
Go to Solution.
Attachments:
laberror.JPG ‏85 KB

Is that mean permission from NI? it was working fine, once i terminated the labview application abruptly when not responding since then i have this problem.
hari

Serial communication from simulink to labview

hello everybody,
i have problems with establishing serial communication from simulink(where the data is generated) to labview (version 2010).
i tried everything but it won t work.can you please help me on this one pleaaase.
thanks ^^
Attachments:
projet labview.vi ‏15 KB

thanks so far for your replies,
to clarify any confusion this is my system in simulink.
the data are decimal values
thanks again, hope i ll receive a reply from you guys soon cause i really need to progress in my project
Attachments:
xxx.PNG ‏20 KB
yy.PNG ‏35 KB

Serial Communication In JAVA

Hi.
I just wanted to know if serial communication is possible using java. If yes, which are the classes used.
Thank you.

I have found javax.comm for Linux and Solaris but not for Windows can any body help me about it .
How can I comunicate using rs232 two computers using Java in Windows.
Tkns
I

Serial communication in j2me

hi,
is serial communication via an rs232 port is possible in j2me to be used in micro devices?
thanx

Check the search engine top right
http://forum.java.sun.com/thread.jsp?forum=31&thread=50052

Fpga serial communication

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