I'm trying to access a device with modbus in VB or C#. I've been searching all over for a simple way to do it. I know that It would be connecting through a TCP Connection, and I know the address of the device. I need to read the input on it (whether of not it's on), and to toggle the relay on it as well.
View 3 RepliesI am developing a software that will monitor/poll serveral Modbus/TCP devices on a network.
I have managed to connect to one device using VB.Does anyone know of a driver or perhaps a 3rd party software I could use that will enable me to connect to more than one Modbus/TCP device?
I have a modbus TCP device that I have managed to connected to through my VB source code.
I want to poll (continueously read) data from certain registers of the device, and store the polled data in a file (text,csv, excel).
I have spent couple of days searching the Internet for some hints, but I haven't succeeded. I need to enumerate all removeable USB storage devices and search for a file. It's important to say, I am looking for a device, which has no drive letter assigned - e.g. Garmin GPS etc.. how to enumerate the devices, indentify storage one and/or access its files?
View 2 RepliesI have spent couple of days searching the Internet for some hints, but I haven't succeeded.I need to enumerate all removeable USB storage devices and search for a file. It's important to say, I am looking for a device, which has no drive letter assigned - e.g. Garmin GPS etc..
View 2 RepliesI was just wondering if you could view the items on a connected Zune device (such as the Zune HD or any of the others. (4GB, etc.))Also, possibly listen to the songs / watch the videos on it with the Windows Media Player codec in the program, and view the pictures in a PictureBox? Is this possible at all? Can I at least view the items? Or is this strictly forbidden?
View 3 RepliesI have a sim card reader, that is a usb-to serial device. It has a sim card inserted. what i need to do is access that sim card to get the data, phonebook and sms for example. I CAN connect to the reader but i cannot send any commands or recieve any data.
What are the commands i could use to access data held on the device. The chipset is pl-2303
I want to develop Modbus RTU Master program ..
I am expert in Modbus communication and I have designed the Modbus pre-programmed remote controls ,, Now I want to interface some Modbus RTU slave devices to my own developed application ...
I am much familiar with the Modbus RTU syntax and I've tried following to initiate the the master query but I am getting initial 3 bytes ok ,, rest of the bytes are changing the values on COM port so slave is not responding to my command ..
CODE:
I want to develop Modbus RTU Master program ..I am expert in Modbus communication and I have designed the Modbus pre-programmed remote controls ,, Now I want to interface some Modbus RTU slave devices to my own developed application ... and looking for kind guidance ..I am much familiar with the Modbus RTU syntax and I've tried following to initiate the the master query but I am getting initial 3 bytes ok ,, rest of them are changing the values on COM port so slave is not responding to my command ..
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Private Sub Button10_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button10.Click
Dim BYTE1 As Byte = 1
Dim BYTE2 As Byte = 6
[code].....
i m working on an application which communicates with PLC machine using Modbus protocol. Now i m able to generate and communicate a modbus data frame with PLC the only problem that i m facing is that in all the data frames of modbus the last ascii characters should be Carriage return + Line feed which should be read by the PLC as 0D 0A that is in Hexadecimal form. But i m not able to do this. The rest entire string is properly read by the PLC but How do I make it read the CR+LF.
View 2 RepliesI have some code I've written that has worked sporadically, and I don't understand the reasons why it succeeds or fails. The code in question is fairly straightforward, a single call to CreateFile() from VB.NET;
Dim Handle As Integer = Win32.CreateFile(KeyboardPath, GENERIC_READ Or GENERIC_WRITE, _
FILE_SHARE_READ Or FILE_SHARE_WRITE, Nothing, _
OPEN_EXISTING, &H80, 0)
The problem is that when I call this, I get the win32 error ERROR_ACCESS_DENIED, but if I remove the GENERIC_READ request, the handle is granted just fine. This has happened before (on a different machine), and I'm completely stumped as to what sequence of events would result in the ability to write to a device and not read from it. The device in question is a Logitech G510 keyboard, and this code has worked fine before on a Vista 32-bit system (I'm now testing it on a Win7 x64 system and fixing all the compatibility issues I can find).My question is, what can cause CreateFile to sporadically fall back to only allowing write access, what am I doing wrong that's causing it to do so, and how would I go about fixing the issue? I've included the full function below - note that with ONLY the GENERIC_READ flag passed, I also am not allocated a handle (same error)
As reference, the particular device path I've been using is \?hid#vid_046d&pid_c22d&mi_00#7&1a08be07&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030} (This is for a Logitech G510 gaming keyboard)
[code].....
I need to interface between a PC and a Microcontroller based Controller to transfer data between the PC and the Controller?
Ive got acces to the register numbers or names in the Microcontroller.
how can i make my program feel if any device or usb device plugged into the computer or unplugged.url...
View 3 RepliesA Problem in accessing a device from VB Windows cannot load the device driver for this hardware because there is a duplicate device already running in the system. (Code 42) This error is because i am using 2 devices of the same company which has the mass usb storage on it and when i install one of the device the other hides. So one is detected the Other is not. It also give a error called designed dragnonacally something...
View 2 RepliesI can get the LAN Device Names (using code below) but how do you get those strings from the "Name" column (see image) that the user can change?
' get list of enabled lan card device names
Dim cat As New PerformanceCounterCategory("Network Interface")
Dim instances As String() = cat.GetInstanceNames()
For Each instance As String In instances
Debug.WriteLine(instance)
Next
I am using VB.NET. How can I run device via USB? I mean device, such as lamp by USB.
View 1 RepliesI`m working on a project where i have connected a FPGA chip to the PCI bus but now i am trying to figure out how to communicate in VB to that device? Normally the device has memory assigned to it in XP (address h00000200 to h0000037F) but i don`t know how to read/Write to that memory directly in VB...
View 2 RepliesHow do you retrive a given device IRQ in VB.Net? I can find no examples of this anywhere.
View 4 RepliesI need to detect a usb device when it is connected to PC.I found next code that is working. But it works only with Mass Storage.Imports System.Management
Public Class Form1
Private WithEvents m_MediaConnectWatcher As ManagementEventWatcher
Public USBDriveName As String
[code].....
Device : USB Scanner
Application : A
Application : B
Let's say there are two applications are running, which are A and B, on windows XP and they all have only one simple form with a text box to receive a data from the scanner. Is it possible to read a number by the scanner and write the number for those two text box on A and B at the same time?
How would a person test to see if a usb device is on? I have a program with a usb reader attached to it and would like to throw an exception if it is not on.
View 2 RepliesI am trying to write a 'simple' program with vs 2005 that recognises my specific usb memory stick so that I can make windows log off or 'lock' when the device is not in any slot. I have found some ready code and I am trying to modify it for my needs. There compiling works but when it doesnt find any of the usb ports.It works by checking each port if it is a usb port and then compares the vendor and produck ID to the given. it seems simple enough but I cant get it to find the USB.
Here is the code:
I need to know, how can we attach an USB to any device and detach an USB. I'm using VB 2008 version. I need to write a code for usb detach and attach in windows xp. Whenever usb is detach from the PC side, i should get a message in command prompt saying that, USB is detached and if you insert an USB , then i should get a message saying that, usb attached.
I'm struck which api should use to communicate with usb , to get info such that usb has been attached or detached?
How do I connect to a device through a USB port. Saying I know what the device ID is. I want to open up serialized communication between me and the device.
View 3 RepliesI have a usb instrument and a driver who's printed output dumps a data string to the computer I need to be able to read this string into vba The driver manual provides the content of the string but no info on how to access the data.
View 1 RepliesIs it possible to use a datgridview as an input device and then transfer the input to variables (one or two dimensional). I am creating a programme that can be used for a widely divergent number if inputs and the grid would be easier for the user rather than me creating a lot of text boxes at design time which may not be required much of the time and a datagridview would probably be preferable.
View 1 RepliesI need to detect a usb device when it is connected to PC.I found next code that is working. But it works only with Mass Storage.
Imports System.Management
Public Class Form1
Private WithEvents m_MediaConnectWatcher As ManagementEventWatcher
Public USBDriveName As String
[code]....
I am trying to figure out how to detect if a device is connected. The exact c# sample can be found here: [URL]
But when I tried to convert it to C# .... I wasted hours!
I googled a lot and changed the declaration of the API many times...
I want to detect when a new usb-device (can be anything) is connected to the computer. I don't need to know what kind of device it is, I just want to know when it is plugged in.
I found this thread: [URL]
I know the solution is in here, but I'm overlooking it I'm afraid. What I want:
USB-device connected > Run function. USB-device disconnected > Run another function.
i'm kind of new to this. I'm using VB2008 and i need to write a code for recognizing a usb's details. like port number and letter and serial number if they have one. if i need to be more specific, then i have to say its for a machine that records data and i need to transfer that data over to my laptop through a gpib to usb cable. the cable has a specific "id" and i need to find that out and type it into the program interface that i'll make when i know how to detect that "id" so it can connect.i've read a few forum posts by others and they are really informative but not what i could use or i could not make it work.(yet)[URL]..and the other links posted there.for reading and helping. thats the clearest way i can explain. if anyone needs a more specific detail, just ask because i dont know if i left out anything else.
View 5 Replies