User's Manual

PIN Pad 791 Programmer’s Manual (PCI POS-A) UDN PM0103-U Rev. 06
Section 9 – Online transaction messages with Master / Session keys 2015-04-20
Page203
Uniform Industrial Corp. Proprietary and Confidential Total 342 pages
Message flow:
HOST Direction PIN pad
Message 70


<ACK> (Good LRC)
<NAK> (Bad LRC)
<EOT> (after 3 NAKs)
Prompt user to enter PIN.

Message 71 or <EOT> when input
timed out or user pressed [CAN]
<ACK> (Good echo)
<NAK> (Bad LRC)
<EOT> (after 3 NAKs)

Display “PIN PAD PROCESSING”
until CLEAR pressed or another
message received.