SE 2.5 How to use hardware triggering

[Highlea]

I have built a simple machine with a loadcell and a stepper drive. Loadcell output (10V) and stepper pulses (quite slow) are fed into a PCI-6221 card via an SCC-68 terminal box.

Loadcell goes into AI0 and AI8 (differential mode) and stepper is fed both PFI 0/P1.0 as a digital input and PFI 3/P1.3 as a counter input.

I want to take a single load reading on each stepper pulse and at the same time increment the counter. I then want to plot load vs stepper pulse count on an x-y graph.

My project has separate steps to input the PFI 0 digital input, the AI0/8 inputs and the Counter as C1.

Under step setup, if I select 1 reading (on demand) all the triggering setup becomes greyed out. I can only select triggering using the N samples or Continuous settings. Where is the 1 reading (hardware) option listed inthe dynamic help?

If I run the project using 1 reading, both the load and steps are recorded against time. Depending on the setting of the time period, I either get multiple records for each step, or miss steps.

The x-y graph displays load (y) vs count(x). I have turned off autoscale, but when I try to set the axis scales and labels, they keep changing when the project is reloaded. In fact the whole system seems a bit unstable regarding the storage and recovery of settings between sessions.

Can anyone help please?

[Hillman]

Hi Highlea,

Thanks for your post.

1) The modes for triggering are dependant on the device your using. It would seem that the PCI-6221 doesn't support  reading (hardware).

2) SE doesn't allow you to save 'session' settings. It is simply a tool to do quick anylsis. You would need to use labview for the functions you've mentioned.

I hope this answers your questions, and please respond if you have another questions.

Regards, 

[Phil_J1]

Hi Highlea,

Using SignalExpress 2.5, eventhough I was able to keep the scale labels after changing them, saving the project, and then reloading the project, it was after running the project that the scale labels would reset. This issue was fixed in SignalExpress 3.0 which released this past summer and has better support for changing scale labels of viewers. Reloading the project will have the settings you mentioned with the scale labels you set.

Phil