| ??? 08/29/11 07:21 Read: times |
#183512 - Neither! Responding to: ???'s previous message |
Just have the Master "poll" each slave in turn:
When the Master has something to send, it uses this as its poll; If the Master has nothing to send, it just sends a poll command. When a Slave receives a command addressed to it, it always responds: the response will contain the data requested by the command (if any) and also an indicator (or indicators) to show if the Slave has something else to send. When a Slave has nothing to send, it just replies with a simple acknowledgement. When the Master receives a reply with a "something else to send" indicator set, it sends the appropriate command(s) to retrieve the additional data - either immediately, or in place of its next "poll". This is the basis of many common protocols - including the MDB protocol used in automatic vending machines: http://www.vending.org/technolog...sion_4.pdf So, if you've ever bought anything from an automatic vending machine, your purchase most likely relied upon this! |
| Topic | Author | Date |
| Multiprocessor Communication 8052 | 01/01/70 00:00 | |
| where is bottleneck? | 01/01/70 00:00 | |
| That's the usual approach | 01/01/70 00:00 | |
| one comment | 01/01/70 00:00 | |
| 9th Bit - How ? | 01/01/70 00:00 | |
| how to use bit 9 for data bytes? | 01/01/70 00:00 | |
| one form of 9th bit use | 01/01/70 00:00 | |
| One byte | 01/01/70 00:00 | |
| One Byte !!! | 01/01/70 00:00 | |
| re: 1 byte - MDB | 01/01/70 00:00 | |
| Strong work | 01/01/70 00:00 | |
| Just as there is a timeout | 01/01/70 00:00 | |
| my reason | 01/01/70 00:00 | |
Protocol should preferably support dry-counting for EOP pos | 01/01/70 00:00 | |
| Methods in brief | 01/01/70 00:00 | |
| At least 1 packet less (sic) | 01/01/70 00:00 | |
| Neither! | 01/01/70 00:00 |