Circular Reference Output Condition

[JayDee]

Hi,
When setting up an output can you make its controlling conditions self refferece its own status? The software does seem to allow it but not sure if it will actually work. (cant test it till next week)

Output#1 = True IF Input#1 = True
OR
Output#1 = True IF Output#1 = True AND Input#2 = False

Input#1 initially triggers output#1. The output should stay active even after the initial trigger is removed (due to the circular refference) and will only be deactivated when Input#2 becomes True.

Do you think this will work?
John.

[figgie]

Hi,
When setting up an output can you make its controlling conditions self refferece its own status? The software does seem to allow it but not sure if it will actually work. (cant test it till next week)

Output#1 = True IF Input#1 = True
OR
Output#1 = True IF Output#1 = True AND Input#2 = False

Input#1 initially triggers output#1. The output should stay active even after the initial trigger is removed (due to the circular refference) and will only be deactivated when Input#2 becomes True.

Do you think this will work?
John.

Ok I am a computer guy so the first question would be why do you want a circular reference? That is never a good thing to do.

The problem is the the OR statement is one or the other but not both. So if EITHER of the statement you posted is true, the condition is true.

So thinking about it.. you need three things


1. You need the Output logic
2. You need a Condition logic. Basically the condition logic will hold the output high as long status shows active.Notice that you I went with a specific of the output channel and not the entire group
3. You need another condition logic which turns the status "active" to inactive based on input #2.

[NGT Racing]

it think we wrote a config that might work for your application,
we wanted left and right high beam to flash oppositly to recognize the car easily when driving down the pitlane with the limiter on, if you send a mail i'll send you the config info@ngt.be

[DarrenR]

That does look like it would work, and there is no problem with using the conditions result in the condition. The result is updated after the condition is calculated so the new result isn't used until the condition is calculated again 20ms later. That said, if you setup a an output like this - output1 true when output1 = false, the output will flash at 25Hz, the same as if you used the flash condition with 0.02s on, 0.02s off, as all calculations are done at 50Hz.

However the Set/Reset function does exactly what you want without the fuss, if i correctly understand what u want to do.

Output1 = set-reset(set:input1 = true, reset:input2 = true)
Output1 will become true when input1 becomes true and will remain that way until input2 becomes true. The set condition has priority so if both inputs are true the result is true.

[JayDee]

Thanks all,
Yes I can confirm using a conditions result inside the same condition does work..... well for my application anyway. cool!

We have actualy used this for a wiper condition.
The wipers power output goes true when the Wipe input is true and continues all the time the wipe input is true. However the once wipe input goes false the wiper output stays true until the park signal is true and the wiper output goes false.

We're running the wiper in high speed only and wired as per method 4 in the PDM handbook.
We have a momentary switch on the steering wheel and a toggle switch on the center console, both wired in parallel to the wipe input of the PDM.

Anyway...its all working fine and we are now working on our power save stratergies and staged shut downs on alternator failure... good fun really!
Cheers all, John.