What does the error message "([6FC0]: Too many PIN requests)" mean?

PCI PTS mandates a rate limit on the number of online PIN entries that can be made during a timeframe using one device. Once this limit is reached, the device returns the error code "([6FC0]: Too many PIN requests)"when entering the online PIN phase during a transaction. Transactions not requiring online PIN are not affected by this and the rate limit is not applied.

You will most likely encounter this error when you are performing a lot of online PIN transactions during testing.