Random arc signal lost

Ah, I think Operate and Release time are referring to the time required for the magnetic field to build up and deplete. So this is a delay between the change of the electrical signal to the coil and the mechanical movement of the contact.
Contact bounce happens when the contacts actually make contact or separate.

Anyway, my point is that these are two different things that should be kept in mind. It's not a question which of the two is right and which is wrong.
Anybody CAN be affected by either one or both.

[edit]
In my oppinion EVERY signal coming from a mechanical contact should be debounced before its used in logic circuitry because ALL mechanical contacts have bounce.
Contact wetting CAN become an issue depending on the environment that the relay is in, but if you happen to be affected by it its a total pain in the neck. So to follow the minimal current guidelines can save you a LOT of trouble.

Just my 2 cents.

rodw wrote: So here is the circuit diagram. You can see that the 7i96 is unaffected. It still draws its 5 mA and the 3 x 270 ohm resistors take 267 mA

Attachment not found

So this becomes my weekend project. To bring my existing circuit in line with the Jury's recommendations.

I thought 7i96's used Pull up resistors. In that diagram, I believe the 4.7k resistor is a pull down resistor, which takes me back to some of my confusion in the beginning of this thread.

Either way, early on you said you used a 1k ohm resistor from the input to the field power ground (which matches your diagram above). Assuming the board resistor actually does match what you drew, that would give you 824.56 ohms, and assuming a 24 volt system, you've presumably only been pulling 29mA this whole time (71mA below the recommended min value).

[edit]
So the above schematics discussed would assume that the common pin of the 7i96 isolated Inputs is connected to ground. If one were to use Field Power as the common then the schematic would look different. (but then the relay contact would be connected to Ground and not 24V)

This has gone to hell in a handbasket quite quickly, so.....
There are several errors on the above posts.

snowgoer540 wrote:
I thought 7i96's used Pull up resistors. In that diagram, I believe the 4.7k resistor is a pull down resistor, which takes me back to some of my confusion in the beginning of this thread.

It has nothing to do with the internal pull ups. Its the internal resistance of the circuit quoted by Mesa that matters. The 4.7k resistor drawn is actually the internal resistance of the 7i96, not a discrete component.

snowgoer540 wrote: Either way, early on you said you used a 1k ohm resistor from the input to the field power ground (which matches your diagram above). Assuming the board resistor actually does match what you drew, that would give you 824.56 ohms, and assuming a 24 volt system, you've presumably only been pulling 29mA this whole time (71mA below the recommended min value).

The 7i76 has a different internal resistance but the same values will apply due to the 10 x rule. I'm not really concerned about what I've done in the past, It what I do in the future for continual improvement that counts.

Aciera wrote: Ah, I think Operate and Release time are referring to the time required for the magnetic field to build up and deplete. So this is a delay between the change of the electrical signal to the coil and the mechanical movement of the contact.
Contact bounce happens when the contacts actually make contact or separate.

Yes, as described in this extract from Omron

Phill, would you be able to shoot me an email? I'll need to be able to communicate the doc edits to you at some point, and I have something else to send your way.

Edit: Oops, I meant to post this in the Feature Request thread.

snowgoer540 wrote: Phill, would you be able to shoot me an email? I'll need to be able to communicate the doc edits to you at some point, and I have something else to send your way.

Edit: Oops, I meant to post this in the Feature Request thread.

I could if I new your email address. Mine is a gmail address and it begins with phillcarter54

phillc54 wrote:

snowgoer540 wrote: Phill, would you be able to shoot me an email? I'll need to be able to communicate the doc edits to you at some point, and I have something else to send your way.

Edit: Oops, I meant to post this in the Feature Request thread.

I could if I new your email address. Mine is a gmail address and it begins with phillcarter54

Oh, I thought you could see them as a Moderator. My apologies! :blush:

Thanks!