We’ve tried hooking up a credit card terminal to a Grandstream HT-386. On newer credit card terminals, it works about 50% of the time. On older credit card terminals, it doesn’t work at all.
What we noticed is that the terminal detects the dial tone after a couple of seconds and then attempts to dial a number to make a transaction. Asterisk never picks up this dial attempt.
My guess is that the ATA box isn’t hearing the dial. Has anyone experienced this? Is there a way to make the ATA box a little more sensitive to hearing the dial. Would a different ATA box make a difference?
I don’t know specifically about your terminal, but most PC based systems allow you to overide the “check for dial tone” feature. If you can assume a dial tone will always exist (if Asterisk is there, I can’t see why not) then you should be able to live without dial tone detection.