Ventana software support forum

Hi there,

I'm trying to create a pulse of between 5-30 days to follow after an amalgamation of two previous pulses.

The formula I'm using isn't working as I'd expected, perhaps someone has any ideas?

I've basically got two pulses:

A Check:
PULSE TRAIN( 0, A Time+"Aircraft Wash Pre & Post", A Repeat Time, 5000)

C Check:
PULSE TRAIN( 0, C Time+"Aircraft Wash Pre & Post", C Repeat Time, 5000)

Where A & C Time and A & C Repeat Times are variable.

These pulses work fine as expected.

What I am trying to do is add a pulse train (Testing) that begins when either an A or C Check has finished ie, the pulse goes back to 0. The pulse train should be for a period of between 5 and 30 days.

The formula I'm currently using is:
Testing:
IF THEN ELSE( A Check=0:OR:C Check=0, PULSE TRAIN( 0, Testing Time, A Check=0:OR:C Check=0, 5000), 0)

Where Testing time is the Variable between 5 and 30.

I think I'm falling down on the repeat time part of the Pulse Train. I basically want it to repeat every time an A or C Check has completed.

Any help would be much appreciated, many thanks in advance.

Gemma

Hi there,

Further to my problem above, I think the main problem I am having is to do with the repeat time.

It seems that at every time step while A or C Check are at 0, the pulse for testing is 1.

I want testing to pulse for a value of 5 when the A or C Check first transitions from 1 to 0. Not for the whole time an A or C Check is 0.

Is there any way round this? I think a solution to this may also solve my duration problem.

Many thanks,

Gemma

I am not completely following the pattern you want to see but if you have specific conditions to turn on and off things I would recommend you stick to IF THEN ELSE and MODULO and stay away from PULSE and PULSE TRAIN. For example

test = IF THEN ELSE(test condition = 1,
IF THEN ELSE(MODULO(Time - test start time,total cycle time) < pulse on time,
1,0),0)


If you experiement with that you can probably get what you want.

Thanks for your reply, however I'm not sure it's what I'm looking for.

To clarify, an aircraft comes in for a service (A Check) which takes 21 days. Directly following this, it will be tested which will take 5 days.

At the moment, my model incorrectly shows that an aircraft is either in an A Check or testing ie, when A check is 1, testing is 0 and vice versa.

I need the model to produce an output the same as in the excel spreadsheet I have attached. This should help to explain what I am looking for.

Thanks again for your reply.

You need something like

aircraft to testing = DELAY FIXED(aircraft arrival for checking,checking time)
aircraft returning to duty = DELAY FIXED(aircraft to testing,testing time)
aircraft being checked = INTEG(aircraft arrival for checking - aircraft returning to duty,0)

and so on. Forget all about pulses and pulse trains.

Thanks so much for your reply, it works just as I need!