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
Page217
Uniform Industrial Corp. Proprietary and Confidential Total 342 pages
screen contents and also reset entry mode.
<ETX> 1 <03>
[LRC] 1 Checksum
Z2 with MAC, response frame
Field Length Value and description
<STX> 1 <02>
Z2 2 Message ID
[status] 1 ‘0’: OK
‘1’: MAC key ID error (out of ‘B’~’E’).
‘2’: MAC key attribute error.
‘3’: MAC value error.
‘4’: Packet format error.
<ETX> 1 <03>
[LRC] 1 Checksum
Message flow:
HOST Direction PIN pad
Message Z2


<ACK> (Good LRC)
<NAK> (Bad LRC)
<EOT> (after 3 NAKs)

Message Z2
(response frame)
<ACK> (Good LRC)
<NAK> (Bad LRC)
<EOT> (after 3 NAKs)


Display string
<EOT> (if received <ACK>)