Measurement Computing DBK70 - Manual (Page 85)

DBK70 User’s Manual 918692 Deciphering PID Messages 7-1
Deciphering the PID $00, $20, and $40 Messages 7
Note: This chapter applies only to J1850, ISO 9141, ISO 14230-4, and OBD CAN.
PID $00, $20, and $40 are legislated PIDs that return a bit-map message indicating which of the other
legislated PIDs are supported by the vehicle. Typically, these three PIDs return a 32-bit value, with each bit
location representing a legislated PID.
To record the PID $00 [or $20, or $40] value, assign the PID to an output channel of the DBK70. Then
with the PC attached and running the configuration software, connect the DBK70 to the vehicle. When the
value is displayed on the PC screen, enter the decimal value into a calculator capable of decimal to binary
conversion. Each bit in the binary number represents a legislated PID value. If the bit has a value of 1, the
PID is supported. If the value is 0, the PID is not supported.
The PID $00 [or $20, or $40] message from the vehicle never changes, so once it has been read and
recorded, the DBK70 output can be assigned to another useful PID.
PID $00 value from vehicle
(decimal)