General Specification Electrical Function gmw3110 General Motors Local Area Network Enhanced Diagnostic Test Mode Specification

 
Value to be determined by 
ECU serial data design 
engineer. 
Service_AA_Msg_Sent 
This is a flag used in the Process_AA_Msgs() function to keep track of whether or 
not a one shot or periodic DPID has been transmitted.
 
YES/NO 
Min_Loops_Since_Periodic 
This is a counter which can be used to force a minimum amount of time between 
the transmission of two periodic DPIDs. This can be used to allow one shot 
DPIDs to be transmitted during loops when the periodics are not allowed.
 
Value determined at 
compile time of the ECU 
software. 
Num_Loops_Since_Periodic 
This is a counter used to keep track of the number of times the 
Process_AA_Msgs() function gets called in the background without sending a 
periodic DPID.
 
$00 to 
Min_Loops_Since_Periodic 
8.19.6.2 Node Interface Pseudo Code. 
Powerup States: 
Call ClearAndDisablePDS() 
Resp_01_Num_To_Send 

$00 
Num_Loops_For_01 

$00 
For (Resp_01_Index 

$00 TO (max_No_of_01_DPIDs - $01) BY $01) 
Resp_01_DPIDs[Resp_01_Index] 

$00 
ENDFOR 
The following logic is executed when a Service $AA message is received by the device: 
BEGINFUNCTION Serv_AA_Msg_Recvd() 
Request_Valid 

YES 
IF (message_data_length > $02) 
No_of_DPIDs 

(message_data_length-$02) /*Calculate number of DPIDs in request*/ 
ELSE 
No_of_DPIDs 

$00 
ENDIF 
IF ( ($Level > LEV_SAFR) OR (message_data_length < $02) OR
(($Level > LEV_SS) AND (No_of_DPIDs < $01)) OR
((No_of_DPIDs > max_No_of_01_DPIDs) AND ($Level = LEV_SOR)) OR
((No_of_DPIDs > PDS_Length) AND ($Level != LEV_SOR)) ) THEN 
Send Negative Response ($7F $AA $12) /*Invalid Format*/ 
Request_Valid 

NO 
ELSE IF ($Level != LEV_SS) THEN 
/********************************************************************* 
Check if all DPIDs are valid (no check performed if $Level =$00) and also 
check how many DPIDs in the request are not already scheduled (if the 
sub-function parameter($Level)is $02, $03 or $04). These checks are performed 
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