MoTeC Global Forum

Hello Everyone ,

Firstly , Thank you for your helps and interest.

We use PDM30 in our rally car so we need to use external kill switch for in case of emergency situation. We tried connect switch to input and set outputs for shutdown but we couldn't run it that way. If you have any sample of comms or any advice for it , Could you share and inform us ? We will be very glad if you help.

What exact function are you trying to achieve?

The Master shutdown function is designed to allow a global output shutdown feature - however it does not power down the PDM.

A PDM will always be 'active' provided there is power to the battery stud of the unit. To completely shut the PDM down, you would require an external isolator.

Otherwise, why did the master shutdown function not suit your use case? Had it been implemented correctly?

Hello Nathan B ,

Thank you for your fast response.

I dont want to power down the PDM.In rally cars we have to do external killswitch outside the car to stop engine functions like fpump , ignt etc. in any emergency situation for safety reasons.Master switch already exists , so I need to do another kill switch on outside of the car but I would like to run this kill switch via PDM. I tried to use PDM's input to connect kill switch for shutdown outputs in emergency but I couldn't run it. I guess Im making mistake with comms or this is not the right way. If Im on the right way can you please share any sample comms ? or How can I run it correctly ? Do you have any suggestion ?

your text doesn't tell what you actually tried and where you have the actual problem?
What settings did you do, what was the expected behaviour and how did the PDM actually behave?

For example what do you mean with "... but I couldn't run it"?
What are you talking about at this point?

What do you mean when you write about "comms"?
The term normally is used for "communication" (for example between laptop and PDM, or between different devices in general) but reading your text I assume you are actually talking about changing the configuration of the PDM, which of course is how you change the functionality/logic of the PDM.

So are you able to read/write the config of the PDM and just need help creating the actual logic to get what you want, or do you have a problem between the laptop and the PDM?

Feel free to upload your actual config of the PDM and tell us where you have your input for the kill switch connected.

Also which kind of switch is it?
Momentary button or toggle switch?
What's the source of the switched signal, ground or 12V? (the PDM needs switches that switch to ground.)

Regards,
Mike

Hello MikeD

Yes , I just need to help about changing / write PDM configuration for external kill switch. I used momentary button for switch. Im able to read/write the config of PDM.I need get info or sample config for creating actual logic to make this kill switch work. Thank you for your interest and sorry for confusion.

Best Regards

then just upload your actual config as this would make it easier to give a proper suggestion.

In general you have to think about what should reactivate the system after the kill button has been pressed but isnt needed furthermore (I prefer to deactivate the kill switch function by pressing another button on the inside of the car like an ignition button or such, any momentary button that you receive already from a keypad or physical button could be that, so when the driver is out on the stage he can intuitively reactivate the system when there is just a fault within the kill switch or such).

I would therefore create a function named "kill engine" or similar with a SET RESET operator, where the set condition is the external kill button input (use something like 0.1 - 0.2 seconds so that risk for false trigger of the kill function is reduced) and the reset condition is any other momentary button which could be used to cancel the kill function later on, if ever needed because of a false trigger/failure of the external mounted kill button.

This newly created "kill engine" function can then be used as the MASTER SHUTDOWN channel, assigned in the GLOBAL SETUP.

The last settings you need to do is going into every output pins properties that you want to be shut off by your external kill button and tick the box SHUTDOWN WHEN THE MASTER SHUTDOWN CONDITION IS TRUE.

Some more thoughts:
I tick the box on outputs for ignition coils, ecu power, injector power, fuel pumps and other pumps that might spill out fluids. But I normally don't tick it on outputs for dash display power (because I prefer to show the active kill engine function to the driver so that he knows why the engine is actually shutting down at that moment).
Last thing is that normaly there should be just one external "trigger" element that should shut down the engine but also kill all the main electrical power, but from your description it sounds a bit like you have the main battery switch different from the engine kill functionality in your car?

Good luck!