| ??? 08/31/05 12:19 Modified: 08/31/05 12:35 Read: times |
#100337 - read the original post Responding to: ???'s previous message |
But, if you now increase the length of your cable
Kai, we are not talking about great distances here, if that was the case I would reject even what you suggest as unsuitable. For distances to, say 6 ft and speeds to, say, 2MHz the ferrite/ schmitt receiver solution works beautifully, if any longer or faster I would unconditionally go TRUE differential, not just "every other wire is ground". read the original post, Per said: "housed in a plastic box on a pole, .... This box/pole is mounted on the machine" Thus I doubt we are talking about several feet. I would never consider terminating a 74H or 74HC circuit, the variable and non-trivial size of the output impedance in one end and the enormous input impedance in the other makes even the best scheme a mismatch. For longer lines whatever they are I use properly terminated 422/485 transcievers (who said that a 422 transciever can only carry 8 bit serial data) where you have an actual impedance match, not a band aid. Erik |
| Topic | Author | Date |
| driving ribboncabel - ESD precautions | 01/01/70 00:00 | |
| on interconnect | 01/01/70 00:00 | |
| Alternative | 01/01/70 00:00 | |
| comments. | 01/01/70 00:00 | |
| Recommended scheme | 01/01/70 00:00 | |
| 74H? | 01/01/70 00:00 | |
| nope | 01/01/70 00:00 | |
| Don't forget series termination | 01/01/70 00:00 | |
| series termination | 01/01/70 00:00 | |
| re: series termination | 01/01/70 00:00 | |
| an, in my opinion, much better way is to | 01/01/70 00:00 | |
| Series termination is the correct method | 01/01/70 00:00 | |
| both? | 01/01/70 00:00 | |
| Series termination prevents overshot | 01/01/70 00:00 | |
| HUH? | 01/01/70 00:00 | |
| Huh Huh? | 01/01/70 00:00 | |
| read the original post | 01/01/70 00:00 | |
| Think about the newbies | 01/01/70 00:00 | |
| That is exacltly why I always push the u | 01/01/70 00:00 | |
| RS485 is a good alternative, indeed | 01/01/70 00:00 | |
| Use a relay driver and sleep well ... | 01/01/70 00:00 | |
ferite bead, series termination, or | 01/01/70 00:00 |