Measurement Computing DBK70 - Manual (Page 75)

DBK70 User’s Manual 928494 Fundamentals of Obtaining Vehicle Data 6-9
During the definition process, multiple messages are sent to the target module to construct a DDP.
Each definition message adds another data item to the user-defined DDP. The following diagram shows
how to derive a DBK70 Message from the information provided in the J2190 document. This example uses
the DDP definition message to add the 1
st data item to a newly defined DDP, Data Packet ID #1 (DPID#).
Sending this message will add engine RPM, a 2 byte data item, to data packet #1.
Transmit additional DDP definition messages, in the same manner, to add more data items to DPID #1.
The following diagram illustrates how another data item is added to DPID #1. At this point, DPID #1
already contains RPM, a 2 byte value, so we’ll offset the data for this next data item by 2 bytes, starting
it at an offset of 3.