| ??? 02/10/12 21:24 Modified: 02/10/12 21:33 Read: times |
#185827 - details Responding to: ???'s previous message |
I have a project to control relays 3km away and send audio one way for a distance of 3km+ for a local factory.
The status of relays should be sent back to the operator's control panel for monitoring. However land phone lines are available between operator and distination on a local exchange(free). I was investigating many methods of doing it, but since phone lines are available, I thought using the phone lines for both voice and DTMF signaling would be most suitable. [edited] I'm also making a control panel for operator, thinking of adding a touch screen for operator with color LCD, maybe an industrial computer with a touch screen. or is it overkill for a simple operation? why not just use switches and LEDs? Mahmood |
| Topic | Author | Date |
| long range RS-485 | 01/01/70 00:00 | |
| Current loop? | 01/01/70 00:00 | |
| Repeaters? | 01/01/70 00:00 | |
| can you use repeaters? | 01/01/70 00:00 | |
| No | 01/01/70 00:00 | |
| Profibus people... | 01/01/70 00:00 | |
| details | 01/01/70 00:00 | |
| just a note | 01/01/70 00:00 | |
| Phone lines... | 01/01/70 00:00 | |
| phone lines | 01/01/70 00:00 | |
| Data collision | 01/01/70 00:00 | |
It just works at slow speeds | 01/01/70 00:00 |