Host response expected, Actions to response codes, Sleep notification – Lexicon DC-2 User Manual
Page 8: Notification packet description, Front panel display buffer, Data description
Lexicon, Inc.
DC-2/MC-1 Serial Communications Protocol
Printed on: 10/19/00
8 of 44
7.1.1.2 Host Response Expected
Following the transmission of the Wakeup notification DC-2/MC-1 will wait for an ACK.
7.1.1.2.1 Actions to Response Codes
ACK
DC-2/MC-1 continues to operate.
NAK Error Code
DC-2/MC-1 will retransmit the Wakeup Notification until it receives an ACK
or it reaches the RETRANSMIT_COUNT. If the RETRANSMIT_COUNT
is exceeded then DC-2/MC-1 continues to operate.
7.1.2 Sleep Notification
By transmitting the Sleep Notification, DC-2/MC-1 indicates the unit is shutting down into a standby mode.
Because the hard power switch could be activated independently of the DC-2/MC-1 system software, hard
power down will not be notified. Acknowledgment of the Sleep Notification is not required. This
notification is primarily for the HOST to know the operating status of the DC-2/MC-1.
7.1.2.1 Notification Packet Description
Application Header:
Command
DC_SLEEP
0x02
Data Count
0
0x00
Application Data:
N/A
7.1.3 Front Panel Display Buffer
DC-2/MC-1 will transmit the front panel display buffer following the update to the DC-2/MC-1 front panel
display. The DC-2/MC-1 front panel display is 2 X 20 ASCII character display. The HOST can control the
operation of this notification message by FPD internal control registers. Individual notifications can be
enabled or disabled and the minimum transmit interval can be adjusted. Transmission of the display buffer
is asynchronous to other host/DC-2/MC-1 communication and will only transmit following the completion
of any communication exchanges in progress or pending. The FPD control register command packets are
described in section 7.3.14 Get FPD Control Registers.
7.1.3.1 Notification Packet Description
Application Header:
Com m and
DC_FPD
0x03
Data Count
42
0x2A
Application Data:
Data[0] - Data[21]
Line1
ch ch ch… 0x00
Data[22] - Data[42]
Line2
ch ch ch … 0x00
7.1.3.2 Data Description
Line1
Data Type:
Null(0x00) terminated ASCII character string.
Max Length:
DISP_LINE_LENGTH defined in Appendix E Protocol Constants.
Line2
Data Type:
Null(0x00) terminated ASCII character string.
Max Length:
DISP_LINE_LENGTH defined in Appendix E Protocol Constants.