unsafe behavior

[El_Tipo]

hello all, iam currently using a SSR-RACK24 with an arduino uno. i have the 70-ODC5 to drive solenoids.

i have 5 leds to simulate the solenoids.

i have observed that right when i fire up the vi (which i'm posting here) all the leds turn on for a a fraction of a second, and then go to the off state. then i can switch them off and on. 

note: i set all the switches to off before running the vi.

this doesnt cut it for me, I need to be certain that no load will be turn on without my concent.

i tried the arduino close, right before the arduino initialized to make sure the port is certanly closed, but it did not help.

how can i dont have that quick on state?

help will be greatly appreciated.

[JÞB]

You need different hardware!!! some type of failsafe to prevent the SSR24 from operating until the arduno is up and running.

[LV_Pro]

As Jeff says, you need some additional hardware between the control hardware and the output hardware, as apparently there is a momentary condition before you have control. Now some hardware drivers have this built in, I don't know your current hardware.

[El_Tipo]

thanks for the replay lv_pro and jeff, i will look and see what piece of hardware can i add in the middle of the arduino and the ssr to avoid this momentary condition.

 any advice into this will be greatly apreaciated.

[JÞB]

One quick trick I use is to throw a pair of relays on the SSR boards power supply.  Require them to be in opposite states to enable the conrtol SSRs.