Appendix - Diagrams
ComTec GmbH
Appendix 8-6
8.3.2. ADC port DRDY / DACC handshake
In the following scope pictures a FAST ComTec ADC model "7072" was used.
Fig. 8.4: ADC port handshake
The minimum DRDY to DACC delay is approximately 211 ns. Since ADC and MPA4T work
asynchronously to each other the response time varies by about 53 ns. The maximum time may
also vary depending on the number of ADC data to be recorded simultaneously (ref. Fig. 8.5).
Fig. 8.5: ADC port handshake with 2 simultanously firing ADC's
In Fig. 8.5 two ADC's are connected and firing simultanously. Since the data is queued for
transfer data acquisition may be delayed by about 211 ns per synchronously firing ADC in a port
row. Thus, the DRDY to DACC delay maybe as long as 211 + 53 + 3 x 211 = 897 ns.