I'm trying to write modbus slave and have one problem: I'm correctly receive requests from master, but when I try to response it's look like something is incorrectly sended to serialport, because when I plug RS485 sniffer - I see both req and res (in HEX).
Hardware: Mac (slave written by me) - USBtoRS485 - ICPCON tGW-715 (TCPtoRTU gateway) - Win PC (software master)
When I'm trying this variant: Win PC (software slave) - USBtoRS485 - ICPCON tGW-715 (TCPtoRTU gateway) - Win PC (software master) everything works.
Libs: libmodbus, h5.modbus (node.js). Doesn't matter - correct request, but no response.
Target PC (for slave) will be on Linux, so Mac is nearly closer than Win.
I'm already have no ideas what to check and how to make it work. What can be wrong?
The Win PC variant is working so, hardware should be fine. Without more details, I would suggests another approach, if your final goal is to use the system in Linux: use a a virtual machine on Windows, with a Linux guest.
I work with ICP DAS tech support, and have used VirtualBox with tM-7561 and I-7561 USBtoRS485 converters, with both Linux and Windows hosts.
I have no experience on Mac, but another option would be trying a Modbus Slave not written by you, for example pyModSlave and see if it works correctly on your Mac, it also shows you the packets sent/received.
If pyModSlave works correctly on Mac, maybe try a software serial sniffer with your slave. On Windows I use the one from HHD Software, it has serial, USB and TCP/IP sniffers. On Mac/Linux you should be able to use Wireshark to sniff USB communications, but I haven't done that yet personally.
Instead of the sniffer, maybe you can use a null modem emulator, so that what you send from a (virtual) serial port will be received on another (virtual) serial port on your Mac, so that you can inspect the data sent/received. On Windows I use com0com, for Linux there is tty0tty that I haven't used yet. Not sure what is available on Mac. Or else just use 2 USBtoRS485 with D+ and D- interconnected, on one port your slave, on the other port a master like qModMaster that shows packets.
Related
What I want to do:
An AI program on a host machine, reading inputs from a camera sensing the screen of the target machine and outputting controls to the target machine via USB connection--programming the host machine's USB host as a USB peripheral connected to the target machine.
What I want to do step by step: (is it possible to implement the steps below?)
Have a host machine A and a target machine B.
Connect A and B with a USB 3.0 Type-A male-male cable.
The USB connection shows up as an HID keyboard device on B.
Write code to simulate key presses on A that sends to B.
(Eg. calling press('F') on a program running on A would type F to B's input)
It shouldn't require any program installed on B.
What I already searched:
USB 3.0 Host to host connection is possible:
https://superuser.com/questions/795053/how-do-i-connect-two-computers-using-usb-3-0
USB 2.0 Host to host connection is impossible:
https://superuser.com/questions/99274/how-to-connect-two-computers-with-usb
Similar questions asked without the assumption that USB 3.0 Host to Host connection is possible:
https://superuser.com/questions/1128365/simulate-usb-keyboard-from-machine
Setting up a computer to act as an HID device connected to another computer via ps/2,usb or another wired connection
https://superuser.com/questions/507921/computer-to-act-as-keyboard?rq=1
Suggestions in ascending order of feasibility:
USB Gadgets
You are using linux, so the default way would be to create/configure/load a gadget driver. Have a look at this tutorial, though for a raspberry, should work on your PC too. However, I could not find any information regarding the use of USB3 - the tutorial assumes your host is using one of it's OTG ports, which your PC most likely does not have. So whether this works with your USB3.1 Type-A-to-Type-A connection you'll need to test.
USBIP
The idea of sharing USB devices (not just keyboards) is not really new. With USBIP you can "export" any local USB device to the network, and your client will need the client-side USBIP driver to access the keyboard.
Dont bother with USB at all, just use Ethernet
I'd simply write two userland scripts/programs that send/receive+execute the keystrokes. Very easy to implement, you're probably familiar with python anyway.
If you absolutely cant have software installed on the client-PC and your Type-C-to-Type-C connection doesnt support USB Gadgets, there's another way. It basically involves the use of two USB-to-serial adapters (~15$) and a serial cable. While this wont be enumerated as a keyboard, but rather as serial port, it's the lowest-effort solution to transfer data without additional software on the client. Both computers will just do file I/O. If your computers still have COM-ports, you can even omit the serial converters!
Trying to develop application using USB modem on Linux. Using Huawei E220 with CNMI=1,1,0,1,0 setup (also tried other CNMI settings none worked) and getting New Message Indications on received message to serial also on received Status delivery message. Is there any other way how to configure the device to enable received SMS alerts ? thanks Under windows machine it is working with no problems. The only problem is linux. Thank you
After a lot of testing and trying to install many linux Mobile Partner drivers finally I came up with an idea to try communication with the modem on different serial port. Linux mounts 3 different serial devices when modem is connected and as i was comparing the modem behaviour on linux to windows i had to connect to the third mounted serial port. I absolutely do not understand why the modem is accessible on two different serial ports but i found out that only one of them can write triggers to serial console. So in case somebody would have the same problem as i had the solution is to test all available serial ports in my case it was /dev/ttyUSB2.
I am on debian and:
I have a USB controller hooked up to a USB port on my PC (Device 1).
I have a male to male USB cord hooked up to another port on the PC that connects to Device 2. (it is a "bridging" usb cord, and has the chip for it)
I want to make them connect to each other as if they were one cord, so neither device knows that there is a computer in the middle.
This would be called a 'Coupler', except that I am using a PC as a coupler.
Here is a (really bad) diagram I made:
What I have done:
I have been able to connect the two devices independently of each other and sniff the results for when they fail to connect. The devices don't send a large volume of data back and forth.
Maybe there is some kind of command tool that I could use, for example (psudocode):
$ couple-usb-ports PORT1 PORT2
You're trying to reinvent the wheel here.
You might consider looking at this link instead.
http://dan3lmi.blogspot.com/2012/10/sniffing-usb-traffic-different.html
Specifically this.
Windows: You cannot directly capture raw USB traffic on Windows with Wireshark/WinPcap, but it is possible to capture and debug USB traffic on a virtual Windows machine under Oracle Virtual Box.
You cannot use a simple PC as transparent USB sniffer without extra (expensive) hardware. An USB bus has always one host (and one or more devices), and the PC can only be the host. This is a hardware limitation.
But you can capture USB data in a Windows machine using Wireshark and USBPcap, eliminating the need for the middle box in most cases.
As this post is tagged Linux, I suppose the controller PC is a Linux machine. Instead of connecting USB ports with a male-male connector, which is all kinds of bad (you are connecting the 5V lines of both machine with each other!), just run Wireshark in the controller PC.
There might be a little work to be done previously, as you have to enable Wireshark for USB monitoring (Particularly in Debian, this is disabled by default), and you might have to install a small driver to enable the monitoring. Have a look at this page for more information.
Once you get it working, Wireshark is an excellent tool for this!
I'm trying to use a Bluetooth OBDII (on-board diagnosis) to connect with a Bluetooth dongle connected to my computer (My OS is windows 7). The dongle connects to the device and assigns it 2 virtual com ports (COM4 for incoming and COM5 for outgoing), But unfortunately I couldn't communicate with this device over the virtual com port. I also attempted to work with winsock library but I didn't find any example for working with Bluetooth OBD and send and receive the instruments. I just found one Bluetooth API for android but it's not useful for me because I want to implement it inside the visual C++ and for PC. and right now I have 2 questions about that :
1. which method is better, Virtual com port or winsock and how ?
2. Do you have any sample code for working with Bluetooth OBD ?
1: Has your device a ELM327 chip? If so, you can setup a serial port over bluetooth, and communicate with that port. I don't know winsock very much, but I think a serial port is better suited for this job.
To set it up, have a look here: http://windows.microsoft.com/en-us/windows7/choose-a-com-port-for-a-bluetooth-enabled-device
Maybe if you can pair with the device, windows 7 will automagically set it up?
2:
You might want to have a look at: http://icculus.org/obdgpslogger/
It's open-source, so you can have a peek how it works. There's also a simulator in the package, which could help you developing/testing. Mostly is Linux based, but it should give you hints where to go. There are also windows installers available for the simulator.
Question: I have one Windows laptop, one Linux laptop and a wireless router.
Now I want to "investigate" the hotmail/windows live protocol.
What I want to do is route network traffic from the windows laptop via ethernet to the linux laptop, capture it on the Linux computer, forward it wirelessly to the router, receive the hotmail response from the router on the linux computer and forward it to the windows computer.
How do I do that?
In essence, switching the Linux laptop between the Windows laptop and the router, to capture network traffic ?
Which program is best for capturing/analysing ?
Please note that for whatever reason, packet capturing with winpcap on the windows computer doesn't work...
Of course you can do this, take a look at wireshark
man tcpdump
On my Mac, I do it like this:
sudo tcpdump -ien1 -s0 -xX -vvv
I don't know how similar tcpdump options are across platforms...
Note, tcpdump also allows you to capture to a pcap file that could then be imported to Wireshark and maybe other gui tools.
As others have mentioned, you can use wireshark (find out how to use filters to remove unnecessary packets in your log). If your Windows and Linux box are on the same network, you do not need that setup to sniff packets. Unless you are using ndiswrapper, you would probably be able to set the wireless network device on the Linux box to "monitor mode" and it will sniff all packets on your LAN. If your device does not support that mode, you can try connecting both boxes to your router physically. That will help you avoid the routing you described in your question.