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

Page49

Uniform Industrial Corp. Proprietary and Confidential Total 342 pages

Message 15 Adjust LCD Backlight Level

Format: <SI>15[contrast stepping code]<SO>[LRC]

Message length: Fixed 6 bytes.

Usage: This message will set the backlight level of LCD monitor.

Message element:

Request frame (HOST to PIN Pad)

Field Length Value and description

15 2 Message ID

[contrast

stepping

code]

1 ASCII character

‘1’ = darkest to

‘8’ = lightest

[LRC] 1 Checksum

Response frame (PIN Pad to HOST)

Field Length

Value and description

15 2 Message ID

[status] 1 ASCII character

‘1’ to ‘8’ for success (echo of contrast

stepping code).

‘F’ for operation fail

[LRC] 1 Checksum

Message flow:

HOST Direction PIN Pad

Message 15 (request)





<ACK> (Good LRC)

<NAK> (Bad LRC)

<EOT> (after 3 NAKs)



Message 15 (response)





<EOT>