User's Manual

PIN Pad 791 Programmer’s Manual (PCI POS-A) UDN PM0103-U Rev. 06
Section 7 – Contactless EMV Level 2 transaction messages 2015-04-20
Page130
Uniform Industrial Corp. Proprietary and Confidential Total 342 pages
Message flow:
HOST Direction PIN pad
1
st
Message T55


<ACK> (Good LRC)
<NAK> (Bad LRC)
<EOT> (after 3 NAKs)

1
st
Message T56
<ACK> (Good LRC)
<NAK> (Bad LRC)
<EOT> (after 3 NAKs)

2
nd
Message T55


<ACK> (Good LRC)
<NAK> (Bad LRC)
<EOT> (after 3 NAKs)

Application Select Response.
2
nd
Message T56
<ACK> (Good LRC)
<NAK> (Bad LRC)
<EOT> (after 3 NAKs)

… … …
Last one Message T55


<ACK> (Good LRC)
<NAK> (Bad LRC)
<EOT> (after 3 NAKs)

Application Select Response.
Last one Message T56
<ACK> (Good LRC)
<NAK> (Bad LRC)
<EOT> (after 3 NAKs)

PIN pad will check if terminal downloads minimum set of EMV Application-related information into PIN
pad. The download process will be failed if there is not enough data in this message. Please refer to
Appendix G for minimum set of EMV Application -related data