Cannt communicate with my device (kind off)

I have a Usb8451 and when I connect it , Measurement and Automotion shows that it is in there, but when I would like to test it ( i believe its the first Icon when you browse to the device) its shaded and I cannot talk to it. The light on the DAQ is on and sometimes it flickers , but cant seem to properly talk to it. Another thing is how the heck can I set P0.0 on? WHats the difference between a port and a line?
Thanks in adcance.

Perhaps you could attach a screenshot of what you are seeing. I have a USB-8451 (which is an I2C/SPI device, I want to verify that you are using this) on my machine, and I have attached a screenshot of what mine looks like in Measurement & Automation Explorer.
Cheers,
Kelly R.
Applications Engineer
National Instruments

Similar Messages

In the latest iOS updates, did Apple change the way Airplay communicate with other devices through Wifi?

Short :
In the latest iOS updates, did Apple change the way Airplay communicate with other devices through Wifi?
Detailed:
We had a glitch with our Apple TV 3A 3-4 weeks ago and had to factory reset it (we reconfigured it with the exact same configuration than before the crash), it's now running iOS 7.0.2, I can't saw which version it ran before the problem though.
It's used in a business environment with 30+ iPads 2, half of them are updated to 8.1.1 and the other half to 8.1.2. We use the latest iTunes version.
Before the glitch that required a reset, all the iPads were detecting and mirroring when needed to the Apple TV, but now the iPads don't see the Apple TV in their list of Airplay devices anymore (but they detect various other devices inside our network).
I have to add that our Apple TV is able to navigate the movie store correctly, so I assume that it's not an internet restriction issue from our end (also, the APple TV do not see either any of the many iPads on its device-detection screen.
We successfully connected an iPhone 5S and an iPhone 6 through P2P Airplay, so it's not the issue, but when we connected the iPhones to our Wifi network (Same as all the other devices are using) the Apple TV suddenly disappeared from the choices.
Hence the reason why I inquire to the possibility that some changes were made in one of the latest iOS revisions, if so, we would require some details so we can adjust our Wifi configuration accordingly to allow the proper detection of devices.
P.S. I tried the basic troubleshooting of Airplay problems with no avail. Airplay button is displaying on the control panel, Airplay do not show the Apple TV at all (so it's not either the trick to display the Mirroring button), we also already proceeded to the suggested devices reboots, so my issue is quite more complex I believe.
Thanks in advance.

PhotogYogi wrote:
I Have the same issue on a brand new iPad mini 2. My battery is only lasting up to 5 hours. I went on chat with Apple last night and they said my battery is fine and its a Safari issue. I'm literally losing 1% every 3-4 minutes. I tried recalibrating my battery, signing out of iCloud, shutting off all locations, turning off background app refresh, restoring network settings, restoring all, and finally restoring from iTunes with no luck. This is just awful. I got this iPad so I could use it on my long flight for a trip I have coming up, and unfortunately, it's not going to last that long, plus I'm concerned about how many times i will be recharging my battery because of this since battery's do have a life cycle dependent on the number of charges. This is frustrating and needs to be fixed ASAP and addressed by Apple.
By the way, Apple told me to bring my device to the Apple Store because it's still under warranty. That's great and all, but I'm going to waste my time if there is no fix for this issue.
Ok so you want Apple to address the problem, but yet you don't want to take it to them just in case they can't fix it? What if they can fix it? Complaining here certainly won't fix it.

Fax from PC: unable to communicate with the device.

Hi,
Im facing this issue where i am unable to send fax through my PC.
Some info:
Device: laserjet CM1415fnw
IP address for laserjet: 192.168.1.250
subnet: 255.255.255.0
gateway: 192.168.1.254
OS: winvista
antivirus: using AVG free edition 2012
both my print drivers and fax drivers are using the same network port which i set manually by creating a tcp/ip port (192.168.1.250).
I am able to communicate with printer to print, scan but not fax.
When i chose the fax driver to print to, it will send the job, and then display the error:
Unable to communicate with the device.
The device may be disconnected, powered off, or its network settings may have changed.
I tried to install using the drivers downloaded from HP and it created a "HP Fax Port" which i tried changing the port to use this instead, still same error.
A command ping to the ip 192.168.1.250 is getting response.
Anyone have any idea? Or could the AV blocking the drivers from communicating to the printer?

Hi AWI,
I am sorry to hear that you are having issues faxing. I would like some more information from you so I can look further into this issue for you.
Could you respond to me with this info:
Are you able to fax from your printer, stand-alone?
What model of printer do you have?
Are you running Windows or Mac?
Have you printed a Fax Test? If yes, does it pass or fail on anything?
Look forward to hearing from you!
R a i n b o w 7000I work on behalf of HP
Click the “Kudos Thumbs Up" at the bottom of this post to say
“Thanks” for helping!
Click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution!

HPlip: "Unable to communicate with the device" error

Hello Arch Community, I've been a user of Arch for a while and most of it just worked out of the box. However, I had my HP 6300 working through a direct connection. But a couple of days ago it just broke.
I've tried everything I could think of to make it back but all has been unsuccesful, I removed the printer and tried to add it again (sorry, old Windows habit, there most of the time works), however, I couldn't add the printer, it fails with the error: "Unable to communicate with the device. Please check the device and try again.", I added myself to the ld group (shouldn't matter, but I did it anyway)
I have cups 1.4.2.
Hp-check:
HP Linux Imaging and Printing System (ver. 3.9.10)
Dependency/Version Check Utility ver. 14.3
Copyright (c) 2001-9 Hewlett-Packard Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.
Note: hp-check can be run in three modes:
1. Compile-time check mode (-c or --compile): Use this mode before compiling the HPLIP supplied
tarball (.tar.gz or .run) to determine if the proper dependencies are installed to successfully
compile HPLIP.
2. Run-time check mode (-r or --run): Use this mode to determine if a distro supplied package (.deb,
.rpm, etc) or an already built HPLIP supplied tarball has the proper dependencies installed to
successfully run.
3. Both compile- and run-time check mode (-b or --both) (Default): This mode will check both of the
above cases (both compile- and run-time dependencies).
Saving output in log file: hp-check.log
Initializing. Please wait...
| SYSTEM INFO |
Basic system information:
Linux carloslicea-laptop 2.6.31-ARCH #1 SMP PREEMPT Tue Nov 10 19:48:17 CET 2009 i686 Intel(R) Core(TM)2 CPU T5600 @ 1.83GHz GenuineIntel GNU/Linux
Distribution:
unknown 0.0
Checking Python version...
OK, version 2.6.4 installed
Checking PyQt 4.x version...
OK, version 4.6.1 installed.
Checking for CUPS...
Status: el planificador de tareas se está ejecutando
Version: 1.4.2
warning: /etc/cups/cupsd.conf file not found or not accessible.
Checking for dbus/python-dbus...
dbus daemon is running.
python-dbus version: 0.83.0
| COMPILE AND RUNTIME DEPENDENCIES |
note: To check for compile-time only dependencies, re-run hp-check with the -c parameter (ie, hp-check -c).
note: To check for run-time only dependencies, re-run hp-check with the -r parameter (ie, hp-check -r).
Checking for dependency: CUPS - Common Unix Printing System...
OK, found.
Checking for dependency: CUPS DDK - CUPS driver development kit...
warning: NOT FOUND! This is an OPTIONAL/RUNTIME ONLY dependency. Some HPLIP functionality may not function properly.
Checking for dependency: CUPS devel- Common Unix Printing System development files...
OK, found.
Checking for dependency: CUPS image - CUPS image development files...
OK, found.
Checking for dependency: DBus - Message bus system...
OK, found.
Checking for dependency: gcc - GNU Project C and C++ Compiler...
OK, found.
Checking for dependency: GhostScript - PostScript and PDF language interpreter and previewer...
OK, found.
Checking for dependency: libcrypto - OpenSSL cryptographic library...
OK, found.
Checking for dependency: libjpeg - JPEG library...
OK, found.
Checking for dependency: libnetsnmp-devel - SNMP networking library development files...
OK, found.
Checking for dependency: libpthread - POSIX threads library...
OK, found.
Checking for dependency: libtool - Library building support services...
OK, found.
Checking for dependency: libusb - USB library...
OK, found.
Checking for dependency: make - GNU make utility to maintain groups of programs...
OK, found.
Checking for dependency: PIL - Python Imaging Library (required for commandline scanning with hp-scan)...
OK, found.
Checking for dependency: PolicyKit - Administrative policy framework...
warning: NOT FOUND! This is an OPTIONAL/RUNTIME ONLY dependency. Some HPLIP functionality may not function properly.
Checking for dependency: PyQt 4 DBus - DBus Support for PyQt4...
OK, found.
Checking for dependency: Python DBus - Python bindings for DBus...
OK, found.
Checking for dependency: Python devel - Python development files...
OK, found.
Checking for dependency: Python libnotify - Python bindings for the libnotify Desktop notifications...
warning: NOT FOUND! This is an OPTIONAL/RUNTIME ONLY dependency. Some HPLIP functionality may not function properly.
Checking for dependency: Python XML libraries...
OK, found.
Checking for dependency: Python 2.3 or greater - Required for fax functionality...
OK, found.
Checking for dependency: Python 2.2 or greater - Python programming language...
OK, found.
Checking for dependency: Reportlab - PDF library for Python...
warning: NOT FOUND! This is an OPTIONAL/RUNTIME ONLY dependency. Some HPLIP functionality may not function properly.
Checking for dependency: SANE - Scanning library...
OK, found.
Checking for dependency: SANE - Scanning library development files...
OK, found.
Checking for dependency: scanimage - Shell scanning program...
OK, found.
Checking for dependency: xsane - Graphical scanner frontend for SANE...
OK, found.
| HPLIP INSTALLATION |
Currently installed HPLIP version...
HPLIP 3.9.10 currently installed in '/usr/share/hplip'.
Current contents of '/etc/hp/hplip.conf' file:
# hplip.conf. Generated from hplip.conf.in by configure.
[hplip]
version=3.9.10
[dirs]
home=/usr/share/hplip
run=/var/run
ppd=/usr/share/ppd/HP
ppdbase=/usr/share/ppd
doc=/usr/share/doc/hplip-3.9.10
icon=/usr/share/applications
cupsbackend=/usr/lib/cups/backend
cupsfilter=/usr/lib/cups/filter
drv=/usr/share/cups/drv/hp
# Following values are determined at configure time and cannot be changed.
[configure]
network-build=yes
pp-build=no
gui-build=yes
scanner-build=yes
fax-build=yes
dbus-build=yes
cups11-build=no
doc-build=yes
shadow-build=no
hpijs-install=yes
foomatic-drv-install=yes
foomatic-ppd-install=yes
foomatic-rip-hplip-install=yes
hpcups-install=yes
cups-drv-install=yes
cups-ppd-install=no
internal-tag=3.9.10.72
restricted-build=no
ui-toolkit=qt4
qt3=no
qt4=yes
policy-kit=no
hpijs-only-build=no
lite-build=no
udev-acl-rules=no
hpcups-only-build=no
hpijs-only-build=no
Current contents of '/var/lib/hp/hplip.state' file:
# hplip.state - HPLIP runtime persistent variables.
[plugin]
installed=0
eula=0
Current contents of '~/.hplip/hplip.conf' file:
[last_used]
printer_name =
printer =
working_dir = .
device_uri = "hp:/net/Officejet_6300_series?zc=HP56B6CF"
[commands]
scan = /usr/bin/xsane -V %SANE_URI%
[installation]
version = 3.9.10.72
date_time = 12/04/09 23:41:37
[settings]
systray_messages = 0
systray_visible = 1
[fax]
email_address =
voice_phone =
[refresh]
rate = 30
enable = false
type = 1
[polling]
enable = false
device_list =
interval = 5
| DISCOVERED USB DEVICES |
No devices found.
| INSTALLED CUPS PRINTER QUEUES |
lpstat
Type: Unknown
Device URI: No se han añadido destinos.
| SANE CONFIGURATION |
'hpaio' in '/etc/sane.d/dll.conf'...
OK, found. SANE backend 'hpaio' is properly set up.
Checking output of 'scanimage -L'...
No scanners were identified. If you were expecting something different,
check that the scanner is plugged in, turned on and detected by the
sane-find-scanner tool (if appropriate). Please read the documentation
which came with this software (README, FAQ, manpages).
| PYTHON EXTENSIONS |
Checking 'cupsext' CUPS extension...
OK, found.
Checking 'pcardext' Photocard extension...
OK, found.
Checking 'hpmudext' I/O extension...
OK, found.
Checking 'scanext' SANE scanning extension...
OK, found.
| USER GROUPS |
dbus hal network video audio optical storage power users policykit vboxusers
| SUMMARY |
error: 4 errors and/or warnings.
Please refer to the installation instructions at:
http://hplip.sourceforge.net/install/index.html
Done.
Albeit it has errors, I can't see how they are releated (cups does have a conf file, but it seems that *my* user can't access it, expected 'couse it's owned by root). Any ideas?

Hi
I had the same problem. The solution is to change the network discovery mode to SLP or add manually the IP address of your printer at the first step of the hp setup wizard. After you install the printer successfully, check the maximum resolution of the driver. Mysteriously, for me the maximum resolution was restricted to 600 dpi so I downgraded to the previous version of HPLIP and got back the 1200 dpi option. Please let me know if you have this issue too. I have posted this question in the hplip forums, but I haven't received any replies yet.

I have VISA3.0,do i need any further instrument drivers to communicate with my device?

If I get Visa 3.0,will that be sufficient to communicate with my device via matlab or will I need
further instrument drivers?

Hello,
It is not very clear what you want to do. For what I understand you have an instrument that you are connecting to a gpib, or serial or tcp port in your computer. Matlab should be able to do the link between VISA and the instrument. Are you using NI-VISA? Are you using LabVIEW or any other software?
If you are using one of our GPIB cards or serial cards, then you would also need the driver for that hardware.
Hope this answers your question. If it doesn�t please provide more description like if you would like to call a Matlab script through LabVIEW or something like that.
Thank you,
Ricardo S.

Can I use virtual bench to measure/communicate with other device by I2C etc?

Hi,
Can I use vitrual bench to measure I2C/SPI/CAN by digital I/O or logic analyzer?
And is it possible using digital I/O to communicate with other device by I2C etc?
Thanks,
Jimmy

You might be able to get it to work (not sure how fast the DIO on the Virtual Bench can go), but for I2C, I would recommend using something that is actually meant for it, like the USB-8451 or USB-8452.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

Best way to communicate with IEEE device

Hi everyone;
I'm using a Magtrol DSP6001 Dynamometer Controller to control a
dyno. It's GPIB, and I'm able to communicate with it swimmingly,
and I've used it it a number of other apps that I've written.
My problem now is, that I need to be reading the device as fast as
possible, but at the same time, setting the torque at regular
intervals. Here's a better explaination:
I'm controlling a stepper motor (which is the main problem, as all the
other motors I have written apps for using this equipment have been
brushless servos) for an acceptance test, and part of the test requires
that the torque be ramped up gradually until the motor starts missing
steps, and the torque at which this happens is recorded. The
problem is, in order to accurately record the torque value, I need to
be reading the device constantly (not a problem, as the controller is
capable of providing 100 samples/second), but at the same time
gradually increasing the torque.
You can see where the problem arises... if I were to multi-thread
this vi, then I would get randomly occurring IEEE errors, but if I have
the data acquisition in the same loop as the torque increase, then I
don't get nearly enough accuracy. Is this something that a
semephore would be useful for? I have heard something about the
IEEE bus being able to handle some sort of syncronization, but I don't
know much about that...does anyone else?
Has anyone else had this sort of problem before?
Thanks, Geoff
Notes: I'm running the controller in open loop mode... for two
reasons. One, it's easier to have a smoother ramp in open loop by
the nature of the commands used to communicate with it, and two, trying
to obtain the PID settings for this motor was getting to be an absolute
nightmare, and I don't think it worth the time, as it's just a ramp,
not a constant torque. Or am I wrong in thinking that?

Thanks for the reply, but I suppose I should have been more clear... it doesn't exactly answer my question.
I have two loops, both of which need to communicate with the
controller. One loop (top in the image) I need to run several
times faster than the bottom loop, as I need greater accuracy in the
readings (more samples).
The bottom loop will run not as fast as possible - as the top loop will
- but will run every say, 20 milliseconds. You might be asking
why that's not in the image, but that's just the bare bones of what I'm
trying to do.
I can't leave them to their own devices as is, since I'll get random
GPIB errors because both might be trying to write at the same time, or
one might write before the top has read, and then the read will return
an error.
I was just wondering what the best way to go about doing this
is... I'll try using queues to do this type of operation, sorta
like you suggested.
Has anyone ever heard of GPIB being able to do synchronized
communication? (as in, is there a way to have two pieces of data,
one being written and one being read, from the GPIB bus at the same
time? Like, being able to read what's been returned by the
controller, but at the same time writing a new command to the bus?)
Message Edited by Novatron on 07-28-2005 03:49 PM
Attachments:
Example.jpg ‏89 KB

Communicate with Modbus device using OPCLabVIEW.

Hi all,
I am using LabVIEW 6i with DSC. I want to connect Modbus device. At some other place I saw that this is very easy with OPCLookout server but we don't have this opc server toolset. So I want to communicate Modbus device using LabVIEW DSC only. Did any one had done it please help me out.
Thanking you.
Vishal

Hi thanks for the reply.
In first para you are talking about some server. Is it OPCLookout / OPCLabVIEW server or anything else please let me know.
As far as the OPCLookout server is concern, we got it. But our excate requirement is as follows.
>>>>> We want to connect our modbus device with FP.
We have flow controller working with modbus protocol. this controller store some parameters. At particular time(daily) we want to get this readings in FP and then pass it to some other PC or main controller. But I am not aware how the lookoutopc server would work with FP. I think that if we could connect modbus with LabviewDscOPC server than DSC will take care for the communication ( Not sure & not know how, if u know please guide me). Due to this only I am ve
ry strict for the LabviewDsc.
In third pare u told about to make driver for modbus. Please guide me how could i do this. I tried to communicate with modbusdemobox (ni one) using serialport vis. but not able to communicate.
Please guide me.
Thanking you.
Regards,
Vishal

Hi my 3rd gen iPod nano is not connecting to iTunes - the error message says there is missing software to communicate with the device. I am running iTunes 10.4 on XP and I have tried all the troubleshooting routes to no avail - anybody help me out?

I can't get Itunes to communicate with my 3rd gen Nano - I've reinstalled iTunes several times but still get the same error message for both mine and my wife's ipod - same version of 3rd gen. All the troubleshooting guide has been followed but still not connecting.
Any ideas?

Never mind, I think. I think I figured it out. There was 1 song (out of > 900!) that somehow had been purchased with the other ID - I have no idea how. Once I deleted that song, it stopped asking.
There may be something with the newest iTunes version too. I didn't think in older versions that the "On this iPod" list of songs was greyed out. But at least it syncs ok.

Will Itunes only communicate with one device per computer?

I get an invalid response from Itunes when my iphone4 is connected to Itunes. I also have a nano that connectes and is working properly. Will Itunes only work with one device per computer. I took the iphone to an apple store and it connects with itunes like it should. I have swapped cables and ports, and downloaded the latest version. Thanks for your help

It is mean to work with multiple devices, although not simultaneously. However I have had exactly the same issue with iTunes 10.7 and Windows7 and a new 16GB iPod touch on iOS6 just this week.
iTunes detects and displays the iPod classic fine, but won't find the iPod Touch when it is connected. The connection is working fine as the Windows OS can see the iPod touch, just not iTunes.
I had a 2nd PC, which has a copy of the iTunes on it and the same media collection - this PC immediately recognised the Touch, so I have gotten around this issue, although I suspect reinstalling iTunes on the original PC may have also fixed it - I have kept a copy of iTunes 10.7.exe so I can reinstall and avoid that POS V11.
I suspect iTunes gets tetchy about hooking in two devices.
Actually as a mostly Windows / Android user, I don't get why on earth do Apple force you to do everything via iTunes anyway? Seems crazy to me. I sort of like the way I can hook up the Android unit and just drag over the files I want without all the darn hoop jumping Apple wants me to do. Anyway... I digress.
So Not sure. Happy I found an easier solution than a reinstall of iTunes. Of course, using a 2nd (mirrored) PC might not be an option for you. Good luck. Wish I had a better / more useful suggestion for you.

Communicate with MTP device using C# desktop application

I want to communicate(Read / Write) with android phone connected with desktop machine as MTP device using C# in Desktop application.
When phone is connected in MTP mode, not as USB drive.
Ram Swami

Hi,
mybe the links below can assist you:>
WPD Application Programming Interface
WPD: Transferring Content
MTP, WPD, OMG
Mark as answer or vote as helpful if you find it useful | Ammar Zaied [MCP]

Communicate with RS485

Hello,
I want to communicate with two device (up to twelve). The problem is that the documentation of my device is very badly written (DSP9000 from Riber if you want to know). It says that for a network communicating I should write for an commands : EOD GID GID UID UID STX MN1 MN2 <command> ETX BCC (for example "r off" is a command). When I write on one device only I use the attached file (ex.vi).
Someone can Help me ?
Lab 8.0
If some information miss please leave me a message
Thanks,
Attachments:
ex.vi ‏23 KB

The first reason your code won't work is that the string you are sending is "@ABCDEF" which means nothing to the controller. You have to send the string of characters that are formatted on page 18 of the manual you attached. I am not sure if you looked at my example code at all.
Your string control is labelled as "String (HEX formatted ASCII" but is actually just normal display with hexadecimal digits and spaces. As a result you are doing a lot of manipulation of the characters to convert them to hex codes. All you need is a string control that has its properties on the right click menu set to Hex display. Then you can type in the hexadecimal string and use the string as is.
I am reattaching your VI with this control set to the example string shown on page 19 of the manual. Try this to start.
Then the question will be are there just a few commands you will execute which you can predefine the string to send along with its checksum character, or will the VI need to be more flexible to send any kind of command. If the latter, you will need to code how the block checksum character is calculated. You would also have to concatenate the special control characters together like I did in the example I attached earlier.
I would also recommend that you attached a serial read function so you can see what response you get back from the controller. If you are still having problems, double check your serial port settings of baud rate, parity, data bits, stop bits.
Also check your wiring. Your subject says you are using RS-485. Is it 2-wire or 4-wire? The manual is a little cryptic in that it starts talking about RS-422 on page 21. But on page 22, lists the RS-485 2-wire and 4-wire setups. But it never truly shows the full wiring of an RS-422 setup.
Attachments:
test_write MOD.vi ‏27 KB

Communication with modbus devices

Hello All,
My name Peter, I am currently exploring what LabVIEW has for instrument communication. I have explored a little on NI-Visa and used it for instrument communication through USB and Ethernet. My next task just now is to see how I can communicate with Modbus devices. I have done some background reading on modbus communication protocol and now have some level of understanding of what it is about. I hope to understand more as I continue to read more materials.
I came across an NI-Tutorial titled Connect LabVIEW to any PLC with Modbus. It is about communicating with a networked PLC using modbus. I followed all the steps described for creating Modbus master I/O Server, Binding shared variables to Modbus Address through the I/O Server and writing to Modbus Addresses in LabVIEW. On running my VI to deploy the shared variable, the following error occured.
Can anyone please guide me on what to do because I do not know exactly what is going ON. I engaged in this excercise with the hope of getting to understand more about Modbus communication and then see how I can apply thesame idea to communicate with the Modbus device available in my Laboratory. Please note that I do not yet know much about modbus communication and I am just learning about it now. I do not have any PLC connected to the network. Could that be the reason for the error? If anyone has got any other relevant document to help me get started with modbus communication I will be happy to have them posted here.
Thanks very much for taking time to read through my post message. Hope to hear a quick response from you.
Regards
Peter

Hi SmithD,
I would like to say thank you very much for making out time to respond to my queries. I have done as directed but still not getting result. Following the wire mode port setting configuration, I stopped the process and then selected the RS485/wire4 as the wire mode. On running the VI, an error pops up with the information that the Visa resource is Valid but the port cannot be accessed. I noticed that If I undeploy the shared bound variable the error does not pop up anymore. I concluded that maybe I was not supposed to have added the VISA configure Serial port in the first place.
Kindly tell me what to do.
My task is to read the holding register from a Modbus device. I have the register map with me, and know the TCP and RTU settings for this device. After the attempts I have made so far I was forced to believe that perhaps the device was not responding. I then resolved to using the QModbusMaster which was previously used to read the holding register. For reasons I don’t not know, It worked well with the TCP communication and returned an error that read " slave threw exception > unknown error". With that, I am now sure that the device is functioning properly, at least with the TCP.
Having obtained result from the TCP using QModbusMaster application, I want to simply do the same using LabVIEW.
Some few questions for which I would want to ask for clarification are:
1.) When using the Modbus Library, do I need to create both master and slave instance to be able to read the holding register? My attempt was to create a Master instance with the RTU parameters. The starting address and number of registers were specified at the input terminals of the Read Holding Register VI. This VI immediately followed the Create Master Instance VI. I was expecting that that would read the information contained in the specified registers and output it at the register value terminal. One challenge with this attempt was that with RTU it didn't work. I tried selecting TCP as the VISA resource. But the device was not showing on the list. I went to MAX to create a new VISA TCP/IP resource under the network devices but MAX could not detect the presence of the device. I am now thinking maybe the device is not supported by NI-VISA and so it will not be possible to use the Modbus Library with it.
2.) If the device is actually not compatible with NI-VISA, can DSC I/O server be used to read the information on the holding register?
3.) Do I need an intermediate device between a Modbus device and the PC to be able to read its holding register?
Please if anybody has got a good suggestion as to what to do to get my task achieved, kindly leave me a post.
Thanks
PETER

"Unable to Communicate with Printer"

I work at home, dialing into the office through VPN. Windows 7. Been using my HP printer flawlessly for 7 months, including up to yesterday, but today, I get the above error. The printer is connected, the wireless is working in my home for all other peripherals attached to it. My work help desk is talking gobblygook to me and can't help. It's something about an IP address. Can anyone help? Work firewall won't let me download the HR Scan Doctor.

Hey @GinaCh,
Welcome to the HP Support Forums!
I understand that you have been using your HP Officejet Pro 8620 e-All-in-One Printer through the wireless connection to your Windows 7 computer fine for months now. However, recently, when connecting to your VPN to print you are receiving the message 'unable to communicate with printer'. Unfortunately, this error message is the exact reason why your printer is not supported over the VPN connection when wirelessly connected.
When you network the printer it comes down to a numbers game. To explain this better I am going to use an example below. When you have a wireless printer on your network it is assigned an IP Address from your router that allows it to communicate with other devices on your wireless network, such as your computer. The first 3 sets of numbers in an IP Address are the same on every device connected to your network.
As an example,:
Printer IP: 192.168.1.8
Desktop Computer IP: 192.168.1.5
Laptop Computer IP: 192.168.1.3
As you can see, the first 3 sets of numbers are identical and the last digit is different on each device.
When you connect over a VPN your computer disconnects from its local connection (your home network that the printer is connected to) and connects to your business network. This VPN connection will change the numbers so your computer that is connected to the VPN will no longer have the first 3 sets the same as the printer.
As an example:
Printer IP: 192.168.1.8
Desktop Computer IP (On VPN): 10.1.10.19
Laptop Computer IP (Not on VPN): 192.168.1.3
If the Desktop computer 'thinks' it's on a different network when connected to the VPN than your wireless printer will be blocked from communication. The 100% way to resolve this issue would be to connect your HP Officejet to your computer through a USB Cable. If this is not an option than the next supported step would be to log into the VPN and open the document you need to print, then disconnect from the VPN and select file and print and everything should work fine.
Now there may be security settings or port settings that may have changed on the VPN which is why the printer is now being blocked from communicating over the network. To resolve this you would need the IT Department for your company to take a look into this issue for you.
I hope this helps clear up any confusion. Should you wish to connect your printer through a USB Cable connection I can certainly assist you with that. Best of luck!
X-23
I work on behalf of HP
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Communicting with a device that uses the K-Net protocol

I have HPLC pump that was built in Germany. The K-Net protocol is used to communicate with the device serially (RS232). Does anyone have any experience/ insight about how to do this. Is there any VI's that will convert ascii commands to this K-Net protocol?? Thanks.
ssmith

Hey ssmith,
Thank you for contacting National Instruments. If you know the commands you will be using to interact with the pump, you can use VISA commands in LabVIEW to handle the communication.
If you do not have the VISA driver installed, you can find that here: NI-VISA 4.2
Also, you might try searching our Instrument Driver Network, as there could be a driver already developed for your pump that would make things easy for you.
Regards,
Kevin H
National Instruments
WSN/Wireless DAQ Product Support Engineer

Cannt communicate with my device (kind off)

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