How to use USB-RS232 to connect the RS232 serial port of another computer?

I connect two PC by RS232 as Fig1. I use command cat /dev/ttyS0 on a PC and echo "hello"> /dev/ttyUSB0 on another PC,but they can’t communicate.

Confusingly,When I use USB-RS232 to connect them on both computers as Fig2,they can communicate。The commands are cat /dev/ttyUSB0 and echo "hello"> /dev/ttyUSB0.

I check the USB to RS232 drivers,and it’s ok.

So what is the reason?


Fig 1

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upgraded to 18.04, now thunderbird will not connect to server

Right after upgrade ubuntu to 18.04 (from 16.?), thunderbird will not connect to the server. Have tried multiple new settings. Posting same question on mozilla community. No problem with upgrade or internet connection afterwards. Using thunderbird 60.8.0. Original POP settings to a comcast server. Incoming – POP mail server, server name, port 995. Outgoing –, port 465.

how to automatically turn off gnome extension when I connect the external monitor (RGB)

So I am using “hide top bar” extension for gnome, but whenever I connect an external monitor (and the screen is located “above”) the laptop screen I can’t move my cursor to that external screen because of the top bar pop-ups instead.

So I am turning it off and on manually whenever I connect an external monitor. Is there a way to automate this?

Ubuntu 64-bit on Windows: Error while powering on – Internal Error and – cannot find the peer process to connect to

I have a problem when using VMware Workstation 15 Player to run Ubuntu 64-bit on Windows 10.

First installation and run is alright, I can power on Ubuntu and work just fine. After I power it off once, I keep encountering the “error while powering on: internal error” or “error while powering on: cannot find the peer process to connect to”.

I have looked at the previous posts and tried running VMWare as administrator or running Services and enabled VMWare Authorization service as automatic. (VMWare Authorization Service is already running in my case, and I have also tried to stop, restart, and start it)

It is even weirder that yesterday, without doing anything extra, I can sometimes power on the machine by just repeatedly pressing the power on button. Tried a few times, and it powers on.

Because it is so irregular, I am afraid that it won’t work when I really need it to. Any advice on what I should be looking on?

Thank you in advance. Alpin

Can’t connect to reverse shell – connection waits forever

I’ve setup a simple Kali Linux machine on AWS and added a security group where all ports are open, then I executed:

nc -vlp 4444 

Now, in my own personal computer I execute a simple Go program:

package main  import (     "fmt"     "net" )  const IP = "MY_PUBLIC_IP:4444"  func main() {     conn, _ := net.Dial("tcp", IP)     fmt.Println(conn) } 

Nothing really happens, the connection waits until it timeouts. Am I missing some configuration?

Thank you.

Connect a Sharepoint List to a SharePoint Document Library

Im using SharePoint Online. I currently have a document library called “Documents” containing circa 500 files. Each file has a column (Description Type) denoting what the document is.

eg Process Map, Geographical Map, Keynote, SOP etc….

I have created a List called “Process Sigma Level”

What I want to achieve is for this list to be connected to the document Library.

So that the list is populated only for “Process Maps”

I can then enter values such as “Current operating performance” into the list.

I don’t want this to be done of the document library, as by using the list I can separate the content and then use the SharePoint Chart option to create visual graphs of performance.

Any thoughts and suggestions?

Think the first challenge is how can I populate the list and for the content to remain up to date based on a filtered list from the document library

Cannot connect to public wifi

I am a beginner of Linux system. I am using Ubuntu 18.04.3 with vmware player 15. I am facing a trouble about how to connect to public WiFi.

I am using bridge connection, which i must use it because i want vmware can stand alone as a PC on the network. When i try to connect to public WiFi, my original PC (win 10) will show up a page that redirect to a terms page, after i accepted the terms, i can connect to internet.

But in the vmware (Ubuntu), i cannot reach any WiFi, it keeps showing up a box that tells me “Activation of network connection failed”. When i reboot the system (Ubuntu), it shows that it connected, but a question mark (?) will appears on the WiFi icon. It seems that it cannot recognize the public WiFi.

i have already chose adapters which are using in my original PC (win 10). I am also tested in my home that tried to connect my private WiFi, and it works, no matter WiFi or Ethernet. But when I tried to connect to public WiFi, it fails.

I found that when Ubuntu told me it had connected WiFi, I could only get inet6 but not inet, and it seems like Ubuntu cannot recognize the DNS of that public WiFi.

how can i fix it?

SSRS 2016 native mode fail to connect SharePoint list datasource

We are using SP2016 with SQL 2016 enterprise edition. SSRS feature is enabled in SQL server and service started. I am able to browse the SSRS portal with http://sqlserver/reports. Also in my SQL 2016 report builder, I can connect to report server http://sqlserver/ReportServer/

Then I setup my first datasource in a report. Connection Type is Microsoft SharePoint List. In connection string field I type in “”. This url can be browsed properly from my PC as well as within SQL server.

In Credentials I tried all the combination I can think of. I have tried my personal account (which is site collection admin) and sql admin and farm admin etc. All results in error message

An error occurred when accessing the specified SharePoint list. The connection string might not be valid. Verify that the connection string is correct.

I have tried to upload the report to SSRS web portal (http://sqlserver/reports) and also fail in same error.

May I know what could be the problem? Is there any patch specific for this issue?