Gems LDS4, Operation Manual, Page: 43 / 71

37 Display Configuration
© 2009 General Engine Management Systems Ltd.
· An open screen n event is triggered by a button press.
Byte 4 of this message can also be used as a page up/ down function as follows:
Byte 4 = 0x00, no change in page.
Byte 4 = 0x01, increment the page number.
Byte 4 = 0x02, decrement the page number.
If byte 4 remains at 0x01 or 0x02, the page will increment/ decrement at the speed at which the
CAN message is received. If the page up/ down function is used, the absolute CAN page number
(byte 3) will only take effect if it changes.
7.2 Configuring the Button Press Mechanism
The LDS4 can receive co-driver button inputs either from the button pins on the connector or
from messages sent on the CAN. To configure the button inputs select Setup | Controller... to
show the controller setup dialog:
To use the button input pins, select Connector pins. To use CAN messages, select CAN ID in
the Button Source section and specify the message type (standard or extended) of the button
message and the CAN arbitration code of the message. Note that page select and button source
messages must be sent to the same CAN port.
The format of the CAN message code can be set to either 16/32 bit or 11/29 bit using the radio
button at the foot of the window:
· 11/29 bit CAN code assumes the arbitration code for the message occupies the bottom 11
bits of a 16 bit standard CAN code or the bottom 29 bits of an extended CAN code.
· 16/32 bit CAN code assumes the arbitration code for the message occupies the top 11 bits of
a standard CAN code or top 29 bits of an extended CAN code. This is used for compatibility
with AN82527.
If using a CAN message for the button inputs, the message must be configured as follows:
· Byte 0 of the message indicates the button that the event is for and whether or not the button
is up or down (pressed):
Bit 0 to 2 of byte 0 indicate the button:
001 = reset button.
010 = select button.
101 = up button.
100 = down button.
Bit 7 of byte 0 indicates the button status: 1 = down (pressed) 0 = up (not pressed).
When the button transitions from down to up, the status of bits 0 to 2 remain to indicate
which button was pressed last.