| ??? 05/17/05 17:45 Read: times |
#93544 - Daisy Blue and Daisy Bell Responding to: ???'s previous message |
Daisy chaining Tx -Rx for 100 boards may work. I would consider is a big gamble to make 100 boards to try.
Daisy, Daisy Let us not confuse "interfaced daisy" with "straight daisy". Neil talk of "interfaced daisy" where board n receive the record and verify it before forwarding it to board n+1. In RS485 we use "straight daisy" where the wires to board n just continue to board n+1. Let us look at daisychaining by "interfaced daisy" 100 boards with crappy interfaces, thus a checksum verification will be required. As the pullup is resistive, I doubt more than 4800 bps (if that can be achieved, but to make it easy let's say 9600 = 1ms/char. Now let us assume a record of just 10 characters and no errors. from 1 to 2 will be 10ms before verification is complete and it can be forwarded from 2 to 3. So to transfer one 10 byte record through a 100 node daisy would take 1 second = good ol teletype speed of 10 bps. Erik |
| Topic | Author | Date |
| Uart Automatic Address Recognition | 01/01/70 00:00 | |
| Can't you... | 01/01/70 00:00 | |
| SADDR and SADEN | 01/01/70 00:00 | |
| For This Application You Will Need.... | 01/01/70 00:00 | |
| Using RS485 | 01/01/70 00:00 | |
| Reasearch | 01/01/70 00:00 | |
| a comments | 01/01/70 00:00 | |
| Fan Out? | 01/01/70 00:00 | |
| Token Ring | 01/01/70 00:00 | |
| You do not have a clue do you..... | 01/01/70 00:00 | |
| How do you know it won't work. | 01/01/70 00:00 | |
| I'm done.... | 01/01/70 00:00 | |
| wrong connection | 01/01/70 00:00 | |
| Just for discussion purpose | 01/01/70 00:00 | |
| But adding your discrete components... | 01/01/70 00:00 | |
| outside of a board | 01/01/70 00:00 | |
| A Pickle | 01/01/70 00:00 | |
| Daisy Blue and Daisy Bell | 01/01/70 00:00 | |
| If you can't change it give it up | 01/01/70 00:00 | |
| If all boards had 10K collector pullups. | 01/01/70 00:00 | |
| horsefeathers | 01/01/70 00:00 | |
| Token Ring | 01/01/70 00:00 | |
| make it first, then design it | 01/01/70 00:00 | |
| 8052 serial communication | 01/01/70 00:00 | |
Off-Topic | 01/01/70 00:00 |