Announcement

Collapse
No announcement yet.

"flashlight" durability tester using CTT timer

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts


  • "flashlight" durability tester using CTT timer

    I have been trying to chomp away at understanding all the timer functions of the CTT timer but thought I should ask if this is possible first.

    I basically want to design a "flashlight" tester and by flashlight i mean a device in R&D stage right now.

    The flashlight is a push on push off type button that I intend to press with an air cylinder.

    I want to use a singe CTT (and perhaps another timer relay to control the solenoid on time) to control the cylinder solenoid to perform the following sequence:

    Turn on flashlight for 40 min
    turn off flashlight for 5 min
    repeat.

    in test rig functionality the statement would be

    Actuate solenoid for say ~2s (to allow travel time) to push button to turn flashlight on.
    timer counts down from 40min
    actuate solenoid for ~2s to push button to turn flashlight off
    timer counts down from 5 min
    repeat.

    I have yet to find a timer mode that can accomplish this. Seems if the duty cycle was equal time on and time off it would be easy but not with different times.

    If a single CTT (and perhaps another timer relay to control the solenoid on time) cannot perform this, have any recommendations on timer relays, single or multiple that can accomplish this? Trying to 100% avoid a PLC (we know a PLC can perform this easy as pie).

    Thanks,
    Mike


  • #2
    Why avoid a PLC?

    Comment



    • #3
      Originally posted by Adisharr View Post
      Why avoid a PLC?
      I would think .. this : I have been trying to chomp away at understanding all the timer functions of the CTT timer

      Comment



      • #4
        Originally posted by Adisharr View Post
        Why avoid a PLC?
        Silly loopholes with the amount of software validation that will need to be preformed on the test rig.

        Comment



        • #5
          Originally posted by Langleym View Post

          Silly loopholes with the amount of software validation that will need to be preformed on the test rig.
          If the PLC software has to be validated, then would the software inside the CTT have to be validated also?

          Comment



          • #6
            Originally posted by Langleym View Post

            Silly loopholes with the amount of software validation that will need to be preformed on the test rig.
            How hard could it be to validate a (roughly) 10-line PLC program for proper operation? Seems much less likely to fail than a cobbled together collection of timer relays.


            SceneryDriver

            Comment



            • #7
              Originally posted by Ryan_Poethke View Post

              How hard could it be to validate a (roughly) 10-line PLC program for proper operation? Seems much less likely to fail than a cobbled together collection of timer relays.


              SceneryDriver
              Agreed!

              Although the code I had for a test rig was more than 10-rungs, having the PLC made life a lot easier when management would ask, "can you do this and that, AND can the results be emailed in a spreadsheet?"

              P1K it is!
              Why worry? If you've done the best you can, worrying won't make it any better

              - Walt Disney

              Comment



              • #8
                Originally posted by RogerR View Post

                If the PLC software has to be validated, then would the software inside the CTT have to be validated also?
                It's different in the fact that the CTT is an OTS items with no custom written software.

                Comment



                • #9
                  Originally posted by Ryan_Poethke View Post

                  How hard could it be to validate a (roughly) 10-line PLC program for proper operation? Seems much less likely to fail than a cobbled together collection of timer relays.


                  SceneryDriver
                  But is it? a PLC is just a bunch of virtual relays

                  Regardless I would be interested still in a strictly timer relay only solution.

                  Comment



                  • #10
                    Did you look at the CTT Timer Repeat Cycle Pg 16?

                    It can use a setpoint and a timed output to make a repeating pulse output.

                    The setpoint starts timing at the start of the output.
                    Drops out the relay at the timed output.
                    Continues to time out to start again.

                    Unless there are some relays used to make a reset, set the sv time to the total on and off time.
                    Set time 45 minutes, timed output 40 minutes.

                    Comment



                    • #11
                      Originally posted by Langleym View Post

                      Silly loopholes with the amount of software validation that will need to be preformed on the test rig.
                      That's certainly understandable. I've been through that before (not often) and it was not pleasant.

                      Comment

                      Working...
                      X