# Curtis 1238 drive direction change



## EV2012 (Oct 13, 2012)

Or, to put the question in a different way: 

How did you lock the drive direction switch to prevent switching while driving by a mistake (e.g. by a passenger)?


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## Ivansgarage (Sep 3, 2011)

How about a switch protect cover.

http://www.summitracing.com/parts/sum-g3902c?seid=srese1&gclid=CJ2TwY7ctb4CFWkQ7Aod3AMAIA





Ivan


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## EV2012 (Oct 13, 2012)

Thank you, that could be a possiblity.

I assumed there would be a controller parameter I haven´t found.

My problem is, that I have already mounted a total different switch, which doesn´t fit to the cover.










Okay, so I think I will programm the CAN controller I built for capturing the motor rotation speed to disconnect the switch by a relay.


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## Plymouth60 (Sep 4, 2012)

I changed the setting of HPD/SRO Type to 3 which prevents reversal while driving. You need to connect the throttle pot micro switch to make this work.
Now what happens when you change the the switch to reverse while driving with your foot on the accelerator, you get slow decelleration. If you lift your foot off the accelerator and on again after the set time, you get reverse torque.

Below is copied from the manual

*HPD/SRO Type*​​​​0–3 Determines the type of HPD/SRO protection. One type of checks is available​
_HPD_SRO_Type 0–3​_​​​​for material-handling vehicles, and two types for golf-style vehicles.​
_OptionBits1​_​​​​[Bit 4] If any of the HPD/SRO checks finds an input sequencing problem, an
HPD/Sequencing Fault (flash code 47) is set.
0 HPD/SRO feature is disabled.
1 HPD/SRO enabled for material-handling vehicles.​
_HPD:​_​​​​If throttle input is received before interlock input.​
_SRO:​_​​​​If direction input is received before interlock input.
The HPD/SRO check is made when the interlock input changes
from Off to On. If the throttle input >25% or a direction input is
On, an HPD/Sequencing Fault is set.
The HPD/Sequencing Fault is cleared by returning the
throttle input to <25% and the direction inputs to Off.
2 Golf-style HPD that allows direction reversal while driving.​
_HPD:​_​​​​If throttle input is received before interlock or direction input
while vehicle is stationary.​
_SRO:​_​​​​None.
The HPD check is made when the interlock input or direction
inputs are Off and the vehicle is stationary. If the throttle
input >25%, an HPD/Sequencing Fault is set.
No SRO check is made with this type, so the order of the
interlock and direction inputs does not matter
The HPD/Sequencing Fault is cleared by returning the
throttle input to <25% and the direction inputs to Off.
3 Golf-style HPD that prevents direction reversal while driving.​
_HPD:​_​​​​If throttle input is received before interlock or direction input.​
_SRO:​_​​​​None.
HPD check is made when the interlock input or direction
inputs are Off. If the throttle input >25%, an HPD/Sequencing
Fault is set. The check is done regardless of vehicle speed, so
reversing direction with throttle input >25% will result in a fault.
No SRO check is made with this type, so the order of the
interlock and direction inputs does not matter
The HPD/Sequencing Fault is cleared by returning the​
throttle input to <25% and the direction inputs to Off.


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## EV2012 (Oct 13, 2012)

@Plymouth60

Thanks for this information! I have to check this out, if it works for me!


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## EV2012 (Oct 13, 2012)

> You need to connect the throttle pot micro switch to make this work.


I have to connect the throttle switch to input "switch 3", right?
And when I press the throttle the switch has to open, right?

It is not really clear for me. 
Thanks for your help!


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## Woodsmith (Jun 5, 2008)

Use a double pole, two way switch, with a center off position?

I think this might work. One pole works the reversing contactors, the other pole cuts the throttle pot switch to cause the controller to stop until the throttle is reset.

On my tractor the reverse switch goes through the centre off position and that shuts off the controller so it doesn't run until I have come off the throttle and back on again.

On my truck I am using a mechanic reversing switch on the motor cables. The switch has a microswitch that cuts the controller off when the switch lever is moved.


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## EV2012 (Oct 13, 2012)

I use a switch with center position.
I connected the throttle switch to switch 3 input.
I enabled driver switch 3 and changed HPD SRO Type into 3.
But if I switch through center position into reverse while wheels are rotating the motor stops hard and goes into other direction ...


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## Ivansgarage (Sep 3, 2011)

EV2012 said:


> I have to connect the throttle switch to input "switch 3", right?
> And when I press the throttle the switch has to open, right?
> 
> It is not really clear for me.
> Thanks for your help!


YES Do you have HPEVS schematic?


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## EV2012 (Oct 13, 2012)

Okay, thanks!
That´s what I´ve done.

So I think I have to test it again. Obviously there is something wrong.


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## Plymouth60 (Sep 4, 2012)

Hi EV2012, I hope you have resolved your issue. I found I had to get the normally closed / Normally open contacts on the speed pot switch the right way around. One way worked, the other way it didn't work correctly. I can't remember which way around it is. Apologies for not responding sooner, but I haven't been on for a while


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## EV2012 (Oct 13, 2012)

Hi Plymouth60,

Thank you very much for your help! 
Yes, I made the same experience, that was my first failure I made, the second was the setup of the controller.
I missed a setting, which was relevant for the function. 
But it is working now. ;-)


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