ANNEX I CRequirements for construction, testing, installation, and inspection
DATA DOWNLOADING PROTOCOLS
2.V.U. DATA DOWNLOADING
2.2.Data download protocol
2.2.4Timing
DDP_019During normal operation the timing parameters shown in the following figure are relevant:
Where:
- P1
Inter byte time for VU response.
- P2
Time between end of IDE request and start of VU response, or between end of IDE acknowledge and start of next VU response.
- P3
Time between end of VU response and start of new IDE request, or between end of VU response and start of IDE acknowledge, or between end of IDE request and start of new IDE request if VU fails to respond.
- P4
Inter byte time for IDE request.
- P5
Extended value of P3 for card downloading.
The allowed values for the timing parameters are showed in the following table (KWP extended timing parameters set, used in case of physical addressing for faster communication).
Timing Parameter | Lower limitValue (ms) | Upper limitValue (ms) |
|---|---|---|
P1 | 0 | 20 |
P2 | 20 | 1 00059 |
P3 | 10 | 5 000 |
P4 | 5 | 20 |
P5 | 10 | 20 minutes |
If the VU responds with a Negative Response containing a code meaning ‘request correctly received, response pending’, this value is extended to the same upper limit value of P3. | ||