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
Page206
Uniform Industrial Corp. Proprietary and Confidential Total 342 pages
Message 72 PIN Entry Cancel
Format: <STX>72<ETX>[LRC]
Message length: Fixed 5 bytes.
Usage: Cancel current transaction and return the PIN pad to IDLE state, used to interrupt
command in process. If PIN pad receives message 72 while processing user input
such as swipe card, enter PIN or key-in data, It will respond with <EOT> to
acknowledge that operation is canceled.
Message element:
Field Length Value and description
<STX> 1 <02>
72 2 Message ID
<ETX> 1 <03>
[LRC] 1 Checksum
Message flow:
In Idle mode (normal condition)
HOST Direction PIN Pad
Message 72


<ACK> (Good LRC)
<NAK> (Bad LRC)
<EOT> (after 3 NAKs)
In PIN/data entry mode (cancel/abort the session)
HOST Direction PIN Pad
Message 72


<EOT>
If PIN pad is in PIN/Data
entry mode or waiting for
tapping/swiping card.