topic Re: Automate CLI commands from a Linux Environment using RS232 Serial Port with the use of Basic Write and Read VISA functions. in LabVIEW

Automate CLI commands from a Linux Environment using RS232 Serail Port with the use of Basic Write and Read VISA functions.

ealmeida — Fri, 19 Aug 2011 20:40:06 GMT

I have to read the output of a Linux OS boot from a unit under test (via a serial RS232 prt), then trigger a write, based on a particular string being read from a buffer (read). There are 25 commands that I have to execute (write) where I have to read the responses of each command and compare the output to make sure the command(s) executed properly.

I am trying to use the Basic Read and Write VISA functions from the LabView tools and I am having no luck.

Re: Automate CLI commands from a Linux Environment using RS232 Serial Port with the use of Basic Write and Read VISA functions.

RavensFan — Fri, 19 Aug 2011 21:42:56 GMT

Can you provide us with some details? Any error messages? A VI that we can look at?

Saying "I am having no luck" doesn't give us any clue as to where we can start to help you.

Re: Automate CLI commands from a Linux Environment using RS232 Serial Port with the use of Basic Write and Read VISA functions.

ealmeida — Fri, 19 Aug 2011 22:28:13 GMT

I have attached a document on what I am trying to do. I am using the attached VI to try and get the just the login at this point. I am not very good at LabView so please forgive me for my ignorance. I am looking for an out line that I can try and get this working...

Re: Automate CLI commands from a Linux Environment using RS232 Serial Port with the use of Basic Write and Read VISA functions.

RavensFan — Fri, 19 Aug 2011 23:20:38 GMT

The first thing I see is that your VI is all out of whack. You took the Basic Serial example and swapped things around in a way that doesn't make sense and won't work.

1. You configure and open the serial port.

2. You check the # of bytes and read the port. Well that is going to be zero because you just opened it.

3. You write something to the port.

4. You wait a bit.

5. Then you close the port. So if you did get any response from the command you wrote, you've just lost it.

Look at the Basic Read Write serial example again.

Then look at the Advanced Serial Read Write. That is a better example in a lot of ways because it does a serial configuration before the loop. Then it does read and write in a loop. Then it only closes the port after you hit the stop button.

Re: Automate CLI commands from a Linux Environment using RS232 Serial Port with the use of Basic Write and Read VISA functions.

Dennis_Knutson — Sat, 20 Aug 2011 21:15:43 GMT

Besides what Ravens had to say, you have a long, long way to go. You have done nothing about the steps you have to run once the login prompt is detected.

I've done this numerous times for linux and RT OS's and what you need to implement is a basic state machine. There are shipping examples to help you get started.

Re: Automate CLI commands from a Linux Environment using RS232 Serail Port with the use of Basic Write and Read VISA functions.

lis@jiang — Mon, 22 Aug 2011 22:25:56 GMT

Hello,

Are you able to successfully use the basic serial read and write example code? Try sending just the basic *IDN? command, and see if you can read that back.

If that works out for you, also take a look at the advanced read and write example. We can incoporate that with a state machine to read and write a series of commands. Here is a tutorial on state machines if you are unfamiliar with them.

Regards,

Lisa

Re: Automate CLI commands from a Linux Environment using RS232 Serail Port with the use of Basic Write and Read VISA functions.

Dennis_Knutson — Tue, 23 Aug 2011 02:55:37 GMT

Sorry, but the *IDN? command has nothing at all to do with a linux os.

Re: Automate CLI commands from a Linux Environment using RS232 Serial Port with the use of Basic Write and Read VISA functions.

ealmeida — Wed, 24 Aug 2011 00:16:40 GMT

I made my state machine and it works pretty good via the VI interface.

Now when inserting the VI (Read and Write) inbetween a Initialize VI and Close VI I get several errors that are enclosed. This is from a TestStand environment.

The other issue is that how do I go about searching the complete output Read String for a substring or parameter within the Read Back string? Can that be done in TestStand and if so how does one go about that?

Re: Automate CLI commands from a Linux Environment using RS232 Serial Port with the use of Basic Write and Read VISA functions.

Eric_L — Wed, 24 Aug 2011 20:26:39 GMT

Hello Ealmeida,

Would you be able to provide the TestStand sequence and VI you are using; at the moment it is difficult to troubleshoot the issue from just the TestStand Report.

Eric

Re: Automate CLI commands from a Linux Environment using RS232 Serial Port with the use of Basic Write and Read VISA functions.

ealmeida — Wed, 24 Aug 2011 20:34:01 GMT

Ok. I will zip this up for you and enclose it. I am at a dead end here and I have been trying everything imaginable to first find out what the Failed Flag is within the log file and secondly trying to figure out how to search the expected response for particular strings within it...

Re: Automate CLI commands from a Linux Environment using RS232 Serial Port with the use of Basic Write and Read VISA functions.

Eric_L — Thu, 25 Aug 2011 23:43:56 GMT

Hello Ealmeida,

The tests are all failing at the moment because you are comparing all the outputs to “abc”. I would recommend processing the string in the Labview and passing a pass or fail out to TestStand. The string comparison and processing would be much easier to do in the Labview environment than passing it back into TestStand.

Eric

Re: Automate CLI commands from a Linux Environment using RS232 Serial Port with the use of Basic Write and Read VISA functions.

ealmeida — Mon, 29 Aug 2011 12:57:00 GMT

Hi Eric. I am not sure on how I would do any compare for a substring within an output string, from a VI prespective.

With that said, I am trying to use the "String Value Test" within TestStand to go ahead and read the output, then search the output from a string.

Example.

1) Write command = ping -c 10 169.254.100.3

2) Output =

ping -c 10 169.254.100.3\r PING 169.254.100.3 (169.254.100.3) 56(84) bytes of data.\r 64 bytes from 169.254.100.3: icmp_seq=1 ttl=30 time=36.1 ms\r 64 bytes from 169.254.100.3: icmp_seq=2 ttl=30 time=32.0 ms\r 64 bytes from 169.254.100.3: icmp_seq=3 ttl=30 time=32.0 ms\r 64 bytes from 169.254.100.3: icmp_seq=4 ttl=30 time=27.9 ms\r 64 bytes from 169.254.100.3: icmp_seq=5 ttl=30 time=60.0 ms\r 64 bytes from 169.254.100.3: icmp_seq=6 ttl=30 time=56.6 ms\r 64 bytes from 169.254.100.3: icmp_seq=7 ttl=30 time=52.0 ms\r 64 bytes from 169.254.100.3: icmp_seq=8 ttl=30 time=48.0 ms\r 64 bytes from 169.254.100.3: icmp_seq=9 ttl=30 time=32.0 ms\r 64 bytes from 169.254.100.3: icmp_seq=10 ttl=30 time=60.0 ms\r \r --- 169.254.100.3 ping statistics ---\r 10 packets transmitted, 10 received, 0% packet loss, time 9036ms\r rtt min/avg/max/mdev = 27.958/43.700/60.049/12.257 ms\r [root@XN1003-03EF28 ~]#

3) Now I want to search that output to make sure I get: 10 packets transmitted, 10 received, 0% packet loss

The String Value Test in TestStand is designed to do this but I cannot get it to work. I set the Limits and Data Source to the appropriate values and it fails every time.

Is TestStand and Labview the correct tools to do this basic function or is TCL/TK the best thing for this?

I would assume NI toolset to be the best but after waisting all this time and money on seats, I am second guessing at this time.

If you have any guidance here, please let me know and thanks so much for your help in advance.

ealmeida

Re: Automate CLI commands from a Linux Environment using RS232 Serial Port with the use of Basic Write and Read VISA functions.

Dennis_Knutson — Mon, 29 Aug 2011 14:28:02 GMT

Have you taken either a TestStand or LabVIEW class? The string value test is NOT designed to search for a substring within another string. Where did you get the impression that it does? It is an EQUAL comparison and you obviously do not have equal strings. You would need to use the TestStand Find() function or as mentioned, a function in LabVIEW (i.e. Match Pattern).