Why can't I netcat into my Rigol DS2072A ? Linux, LAN, etc.

[LinuxGuy123]

Hi.

I'm trying to send some SCPI message to my DS2072A and I'm not getting any responses.

It is connect to my local network via DHCP at 192.168.1.125.  I can ping it with no problem.

My workstation is running Fedora 36 Linux.

I've tried to send several commands, such as:

Code: [Select]

echo ":DISPLAY:DATA? ON,OFF,PNG" | nc -w1 192.168.1.125 5555 | dd bs=1 skip=11 of=image.png
echo “:SYST:LANG?” | nc -w1 192.168.1.125 5555

# echo ":DISPLAY:DATA? ON,OFF,PNG" | nc -w1 -4 192.168.1.125 5555 | dd bs=1 skip=11 of=image.png
^C
0+0 records in
0+0 records out
0 bytes copied, 136.488 s, 0.0 kB/s




I've tried this both as a regular user and as SU.  What am I missing ?

Thanks

Do I have to enable something on the scope to enable it to reply to SCPI commands ?

Are there any simple tests othre than ping <scope IP> to test why it isn't work ?

My scope is software version 00.03.03.sp1.  Do I need to update it before SCPI commands will work ?

[gnif]

I've tried this both as a regular user and as SU.  What am I missing ?

There is no need to do this as `root` as your regular user can open outgoing ports using netcat just fine. While I can't speak to the issue you're having as I am not familiar with the device or the protocol, you should know that unless you specify `-n` to `echo` it will also output a carrage return, which might be messing things up.

For example

Code: [Select]

echo -n ":DISPLAY:DATA? ON,OFF,PNG" | nc -w1 192.168.1.125 5555 | dd bs=1 skip=11 of=image.png


[LinuxGuy123]

There is no need to do this as `root` as your regular user can open outgoing ports using netcat just fine.

OK.

While I can't speak to the issue you're having as I am not familiar with the device or the protocol, you should know that unless you specify `-n` to `echo` it will also output a carrage return, which might be messing things up.

Are these commands supposed to be sent with a CR or a CR/LF or nothing ?

Thanks for the reply.

[gnif]

Are these commands supposed to be sent with a CR or a CR/LF or nothing ?

That's what I meant, I am unsure if they are, but the `echo` command by default will output a line-feed (\n) if you do not specify the -n switch if you are unaware. This can and has caught me out on occasion in the past.
You can explicitly output a line feed (\n) or a carriage return (\r) with `echo` by using the -e switch, for example

Code: [Select]

echo -ne "SomeText\r\n"

As to why it's not working, if it isn't this, someone here with more experience will need to provide an answer I am sorry.

[LinuxGuy123]

I still can't connect it over the LAN, but USB works.

Code: [Select]

echo "*IDN?" > /dev/usbtmc0; cat /dev/usbtmc0
RIGOL TECHNOLOGIES,DS2072A,DS2D164752690,00.03.03.SP1

I'll update the firmware and report back.

[mag_therm]

I use ssh on linux but have not used nc, so not familiar.

Firstly, are you sure that nc is listening as a server on the Rigol?

To check that , you could run nmap like this, (install it first if you don't have it).

nmap -Pn 192.168.1.125

IT takes a minute or two. That will tell you all ports that are open and have servers.

Here is an example of nmap response:
$ nmap -Pn 192.168.1.16
Starting Nmap 7.80 ( https://nmap.org ) at 2022-08-23 15:31 EDT
Nmap scan report for 192.168.1.16
Host is up (0.0054s latency).
Not shown: 998 filtered ports
PORT     STATE SERVICE
21/tcp   open  ftp
3389/tcp open  ms-wbt-server

Nmap done: 1 IP address (1 host up) scanned in 4.89 second

[LinuxGuy123]

$ nmap -Pn 192.168.1.125
Starting Nmap 7.92 ( https://nmap.org ) at 2022-08-23 15:30 MDT
Nmap scan report for 192.168.1.125
Host is up (0.037s latency).
Not shown: 997 closed tcp ports (conn-refused)
PORT     STATE SERVICE
80/tcp   open  http
111/tcp  open  rpcbind
5555/tcp open  freeciv

Nmap done: 1 IP address (1 host up) scanned in 0.70 seconds

I updated via USB.  I'll post the process in another thread.

My network connection works now.

$ echo "*IDN?" | nc -w1 -4 192.168.1.125 5555
RIGOL TECHNOLOGIES,DS2302A,DS2DXXXXX,00.03.06

Turns out these scopes have an HTTP server in them.   

Thanks for your help. 

[LinuxGuy123]

I use ssh on linux but have not used nc, so not familiar.

Have you logged into a Rigol scope using ssh ?

[mag_therm]

No, I have a new GW Instek GDS 1202B.
So far I use USB media in the front socket  to transfer files.
There is a big manual about comms but I have not had time yet to get into it.

But if your Rigol had ssh server up, you would have seen it on nmap.