LabVIEW
Reading a button
Solved!
@mcduff wrote:
I think one problem here is that the task is not well defined.
I made a "Windows" system for a portable spectroscopy measurements that contained a Class 4 laser. However, all of the safety in the system was hardware based. I was able to read the digital lines with a cheap NI DIO board of the hardware interlocks easily and respond to them. The lesson here is that software had no control over the interlocks and if Windows/software crashed then no safety issue. If the hardware interlocks were not engaged no matter how many times I sent a command to fire the laser, it would not fire. Safety did not depend on software.
Does the hydraulic press here have hardware interlocks that will protect a user in spite of the software? If so the lack of experience may not be a problem. But if the system is relying on software for safety without any hardware, I would be concerned.
I was more concerned with stuff like "what if the user spams the button?"
@govindsankar wrote:
Yes the hydraullic press have a hardware based system. It will be a two button system. So that user will have to use both hands to operate the system. Secondly I am planning to use a IR sensor to detect anything in the vicnity. So there is an emergency stop button in the hardware of the press. I am planning to use the IR sensor to program in a way that when the user comes near it the stop button is triggered. And system is stopped.
Why use software for that? Connect the light curtain to the stop button.
@govindsankar wrote:
Well we are not making any difference to the hydraullic press. We will just use a button to scan the serial code and the hydraullic press will work as usual and afterwards there are buttons to confirm whether the process was successful or not based on visual inspection. So for this I need a button reader, but I understood we need to use a DAQ device to read a button. I am also using the DAQ device to read digital voltage. So for this I am planning on using
MCC USB-1208FS-Plus/LS/1408FS-Plus Series: Multifunction USB DAQ Devices.
https://digilent.com/shop/mcc-usb-1208fs-plus-ls-1408fs-plus-series-multifunction-usb-daq-devices/
So as anyone worked with this. Or do you recommend something else. Kindly let me know. Thank you.
I haven't worked with that one, but it seems similar enough to NIs 6001, so it should be plenty for what you're describing.
The more info we get from you (and the other posts in the forum), the more interesting it sounds. Very cool. 🙂
Often times process controllers have their own DIO. Does your hydraulic press controller have a button on it?
It also sounds like you might be programming the whole thing in LabVIEW, so maybe that's why you need to read a button.
A DAQ will definitely work to read a button, but then again, so would a $3 Arduino clone. Safety will need to be implemented somewhere other than the device that reads the button anyway so I wouldn't feel too bad about using something cheap to sense the button press.
There are many devices that'll do what you need it to. Any Arduino, Raspberry Pi, Beaglebone, ESP8266 or ESP32, etc will do the trick. They won't be 100% bulletproof but all they're doing is reading a button.
Again to emphasize... you need real, actual, hardware-level safety for this anyway, so you MUST plan to have false button presses sensed in some way. Thus, I don't feel like you need a particularly heavy duty button pressing sensor.
