User's Manual

PIN Pad 791 Programmer’s Manual (PCI POS-A) UDN PM0103-U Rev. 06
Section 5 – Administration and maintenance messages 2015-04-20
Page51
Uniform Industrial Corp. Proprietary and Confidential Total 342 pages
Message 17 Request random number
Format: <SI>17<SO>[LRC]
Message length: Fixed 5 bytes.
Usage: This message is used to request PIN Pad to generate an 8bytes random number block.
This random number is generated by hardware TRNG that is certified with sufficient
security.
Message element:
Request frame (HOST to PIN Pad)
Field Length Value and description
<SI> 1 <0F>
17 2 Message ID
<SO> 1 <0E>
[LRC] 1 Checksum
Response frame (PIN Pad to HOST)
Field Length Value and description
<SI> 1 <0F>
17 2 Message ID
[RndBlk] 16 Random number block generated
by PP791.
Format: hexadecimal string.
<SO> 1 <0E>
[LRC] 1 Checksum
Message flow:
HOST Direction PIN Pad
Message 17
(Request frame)


<ACK> (Good LRC)
<NAK> (Bad LRC)
<EOT> (after 3 NAKs)

Message 17
(Response frame)
<ACK>/<NAK>
/<EOT>


<EOT>