Suggested Poll Timing vs Human interactivity

[andreIsGold]

Hi,
I'm writing an application to accept some money with a note acceptor and a coin acceptor. My problem is that I have a threshold for the money that I can accept for a session.
I was thinking to inhibit the Coins of each acceptor that can take me over the threshold. Because, as the money get inserted the threshold value decrease, the coins inhibited change time by time.
I was so wondering witch should be the poll interval that allows me to check the money inserted and inhibit the appropriate channel before other money has been inserted?
Or there is any reasonable poll interval that make me secure and I have to use other technique?
I had thought to disable all the devices to update the value of the threshold: I mean to do a poll cycle like that:
1)Disable All
2)Update Threshold
3)Update device configuration.
4)Enable all
5)Wait for ???

[davebush]

Note acceptors are inherently slow enough that you can inhibit the acceptor after the note has been read.

It is probably not even theoretically possible to achieve exactly what you're after with coin acceptors. If a person puts two coins in as close as possible, then there's a good chance it has already got too far on the 2nd coin before it notifies the paylink of the first!

What you can do is to use a routing acceptor, and use the "cash box" path as a reject / return. You can then use the the Paylink automatic switchover facilities to switch from "hopper" to "cashbox" (return).