Some questions on efficient serial read and speeding up data processing

[Dennis_Knutson]

A terminal echo is typically the instrument returning the command that it received. It would not be used unless you are especially concerned with the command being scrambled during transmission. You have not attached the manual so it's all speculation.

[labview12110]

http://www.kurzinstruments.com/Documents/Manuals/KURZ-155-userguide.pdf

This is it.

[Dennis_Knutson]

I don't see anything there about the serial commands. Just controlling it from the front panel.

[labview12110]

It has a brief blurb in it about the serial but otherwise that is it. hence why I am having so many problems. Any idea why an activex program would be able to sample at 25ms, while mine can only sample at 2 seconds? I did notice that it says in one brochure that the screen updates every 2 seconds on other models, so maybe that is the same for my model and because I am reading from terminal echo on, and not just straight querying it every time that I am only getting it every 2seconds. if that is it then problem solved! otherwise I am out of ideas on how to make the sampling rate better.

Found another manual that talks about some of the serial commands for data logging

http://www.proconsystems.com/product_manuals/dcn_360204-6.81rev.buserguide-psi~155~.pdf

[RTSLVU]

I wuold say the other program is using some commands to poll data from the device, not just displaying data sent out at teh screen update rate.

If these commands are not avaiable (have you contacted th ecompany sometimes there is a seperate 'programming manual') then I wouild use some sort of serial port sniffer to see what the other program is doing and how.

Portmon works great for this 

[Dennis_Knutson]

I second the use of portmon. Turning echo off should help as well if they are using echo in the fashion I described.

[labview12110]

Portmon does not work on my win 7 machine. I did contact thecompany and those are the only commands.

[billko]

Man, I looked at the vendor web site and they seem to really not want you to be able to access the euqipment except through their stuff.  On the other hand, they give you enough inofrmation on the physical guts of the thing that I could probably build one from scratch...

[labview12110]

It was also great to learn that their lead engineer barely spoke any english! That was a fun 30min phone call to learn nothing.

[labview12110]

The other program is doing the exact same thing. X command, read string. Found a compatible serial port monitor. Once called from labview it essentially does it indefinitely. There is no off option, until labview is closed and the port plug is pulled and it crashes.

It also does not update properly however. If x is sent too quickly following the previous x it resets the output back to time. So I never get to the flow line. So for example if I use the highlight option I get a flow value because it had enough time to read. The documentation for this program claims to be querying with x every 25ms. Im a bit skeptical on that....anyway, if it does the same thing my serial read option I attach ed earlier should be fine to use but this doesnt explain the slow data read! I definitely have to have a wait of at least 500ms to read both lines of the x response before querying again that much I know. I also have two pumps connected to the same serial to use ni box and both are open at the same time but I cant see how that could change things when the same setup exists on the windows xp machines they currently use!