AIU

I would try a different accessory port. If it does the same thing it is probably not in the AIU.  Sometimes, a single port will malfunction. I have one with a switch port that will not work.

I check every port it looks like the relay will not stay energized ons for a sec

@jc63 posted:

... The s5 key claims it turns off momentary but it still will not stay on. 

I don't understand what you're saying.  The S5 key is indeed momentary.  It should not stay on.  Are you suggesting it should stay on?

If you want the AIU relay to turn the accessory on and stay on, then press S3 (ON)....and when you want to turn the accessory off, then press S4 (OFF).

That is what i am doing I press the S3 key on the unit gos on for a sec then turns off.  Will not stay on when you press the on button

What happens when you press the S5 key?  Does the relay click "on" for as long as you press S5...and then click "off" when you release S5?

no click when you press s5   when you press on key you here a click then it gos off

You may want to determine if the issue is with the AIU or the device you on the layout. Do you have another device that you could hook up to the AIU and test for proper functionality?

I have one AIU where 1 and 2 sometimes stick in the ON position, when it should be momentary. Had to stop using these two AIU ports.

What is the accessory that you are having trouble with?

It looks like  there is switch relays in ports that are in accessory  ports.   Could be manufacturing error

THE RELAY IS NOT DESIGNED TO STAY ON It uses a capacitive discharge system capacitor charges and when you push the button it should fire the switch coil, if it were to stay energized you would burn up the coil it's designed too only be on momentary!

Alan

@jc63 posted:

It looks like  there is switch relays in ports that are in accessory  ports.   Could be manufacturing error

If you mean you opened the cover of an AIU, it should look something like:

There are 30 relays. 10 are for the ACC ports.  For a given ACC port (1-10) the ACC relay for that port clicks-on when you press the S3 (ON) button or for as long as you hold down the S5 (ACT) button.   The relay clicks-off when you press the S4 (OFF) button assuming it was previously turned on by S3...or is clicks-off when you release S5.

What may seem curious is there are 2 relays for each SW port or 20 relays total to handle SW action.  When controlling an SW port, one relay clicks-on/off in exactly 0.5 seconds when you press "Straight".  The other relay clicks-on/off in exactly 0.5 seconds when you press "Diverge".

For all AIU versions I have seen, the SAME relay component is used for all 30 relays.  It is software in the TIU/AIU combo that make these garden-variety relays behave like a momentary or latching relay.

@Alan Mancus posted:

THE RELAY IS NOT DESIGNED TO STAY ON It uses a capacitive discharge system capacitor charges and when you push the button it should fire the switch coil, if it were to stay energized you would burn up the coil it's designed too only be on momentary!

By "relay" are you referring to the relays inside the AIU?  The relays used in the AIU (whether for SW or ACC) are NOT of the capacitive discharge type.  The SW relays indeed turn on only momentarily (1/2 second to be exact) when you press the "straight" or "diverge" button.  The 1/2 second timing is implemented in software...specifically there is microprocessor code in the TIU that sends a command over the TIU-AIU cable to turn on a particular SW relay...then exactly 1/2 second later another command to turn off that particular SW relay.

@jc63 posted:

no click when you press s5   when you press on key you here a click then it gos off

I found this video I no doubt posted in a previous OGR thread about the AIU a few years back showing ACC and SW port operation via DCS handheld remote.

The video uses simple bulbs to illustrate the momentary behavior of the SW ports and the momentary or latching behavior of the ACC ports.  I don't know if it's universal between different AIUs but in this case you can hear a different sound when a relay turns on vs. when a relay turns off...like a "click" on followed by a "clack" off.  This click-clack sound variation might help interpret what's going on if you don't have a bulb or whatever to indicate what the relay is doing electrically.

Separately, if you do some OGR searching, it seems years ago there was some issue with a version of TIU software that did not play well with the AIU...memory a bit fuzzy on this.  In any case, for the record tell us what version of TIU software you're running.  There is NO software version for the AIU so no need to worry about that. Did your TIU/AIU ever work or did you just get the AIU and/or TIU off eBay or whatever? 

"THE RELAY IS NOT DESIGNED TO STAY ON "

If that statement were correct with regard to accessory relays, I could not run the lifts in my #97 coal loader and my ancient log loader.  They stay on until I turn them off.  The discharge features work as long as I hold the S5 button--so the relay stays on.