PHS8-P ttyUSBx communication question | Telit Cinterion IoT Developer Community
July 13, 2016 - 10:07pm, 2568 views
I am a new user and I have already made some progress. First of all, let me give you some details about my setup:
- PHS8-P terminal from MC Technologies.
- Firmware version 3.32
- I am able to communicate to the serial port of the terminal from windows using PUTTY.
- AT^SDPORT = 4
- I have configured the context (AT+CGDCONT).
- I am able to use the wwan0 interface in a linux computer (issuing the AT^SWWAN command from the windows computer).
As you can see, I am at a point where I am using two computers, but I need to use only one (linux) and do everything using the USB connection. My specific question is this: from linux, how can I communicate to the ttyUSBx ports? If I can do this, I can change the AT^SDPORT setting to 3 and do everything via USB from linux (I also need to use the GPS functionality). I have tried different ways to communicate to ttyUSBx without success.
Please let me know if you need more information.
In Linux you do that more or less in the same way as you do it in Windows - you need some serial port terminal program (for example Minicom) to communicate with ttyACM or ttyUSB ports. Please note that you may not be able to communicate on all enumerated ports - the same as in Windows.
I changed AT^SDPORT to 3. I had a hard time finding the application port (AT^SQPORT), but finally I found that it was /dev/ttyUSB2. It took me a long time to figure this out, but now I can reproduce it consistently. The behaviour is the same with PUTTY or minicom (both in Linux). This is what happens. When I first open putty/minicom, I type AT enter and nothing happens (I see absolutely nothing in the screen). Then I have to close putty/minicom and reopen it. The second time I open putty/minicom it works (I type commands and I get the response). If I close putty/minicom and reopen it, I can see nothing again, but I type AT enter and close. Then reopen it and it works. It works one time no, one time yes. So it seems like there is some synchronization problem. I was reading the AT command guide and it says that the flow control (AT\Q) doesn't affect the USB ports. Do you have any suggestions as to what I can do or check to fix this issue?
I think that the problem is not on the module side but Linux system. Please check the syslog to see which ports are enumerated when the module is connected. Please make sure that you close the port properly each time. There might be a situation when some resources are not released.