Talk:SDI-12: Difference between revisions
No edit summary |
No edit summary |
||
Line 11: | Line 11: | ||
[[Special:Contributions/134.121.69.76|134.121.69.76]] ([[User talk:134.121.69.76|talk]]) 18:18, 5 May 2014 (UTC) |
[[Special:Contributions/134.121.69.76|134.121.69.76]] ([[User talk:134.121.69.76|talk]]) 18:18, 5 May 2014 (UTC) |
||
==Similarity to RS-232== |
|||
SDI-12 isn't all that far from RS-232. Combine the Tx/Rx lines, add a +12Vdc line and viola, an SDI-12-compatible physical interface. Set your terminal to 1200/7/E/1 and now you are protocol-compliant as well. Now also consider the fact virtually every RS-232 interface produced in the last few years, now and into the future are/will be TTL-compatible (e.g. 5V logic, not 12V, because of USB) and it should be apparent how similar SDI-12 is to RS-232. |
|||
[[Special:Contributions/134.121.69.76|134.121.69.76]] ([[User talk:134.121.69.76|talk]]) 19:37, 5 May 2014 (UTC) |
Revision as of 19:37, 5 May 2014
Frankly it's a poxy protocol that should be deprecated.... Slow, difficult to implement in modern uarts coz it uses the break sequence... BUT it's human readable... (fire up the old TRS-80 to read the data!). --PeterMarkSmith 07:18, 28 November 2006 (UTC)
More expensive?
The standard document itself contains a section titled "Advantages" which lists, among other benefits:
- Sensors can use low cost EEPROMs (electrically erasable programmable read only memory) for calibration coefficients and other information instead of internal trimming operations.
- The use of a standard serial interface eliminates significant complexity in the design of data recorders.
These wouldn't have been thrown in as an afterthought. It seems wholly incorrect to assert that SDI-12 devices "tend to be more expensive" based on the unfounded assumption that "extra components and chips" result in a higher overall price.
134.121.69.76 (talk) 18:18, 5 May 2014 (UTC)
Similarity to RS-232
SDI-12 isn't all that far from RS-232. Combine the Tx/Rx lines, add a +12Vdc line and viola, an SDI-12-compatible physical interface. Set your terminal to 1200/7/E/1 and now you are protocol-compliant as well. Now also consider the fact virtually every RS-232 interface produced in the last few years, now and into the future are/will be TTL-compatible (e.g. 5V logic, not 12V, because of USB) and it should be apparent how similar SDI-12 is to RS-232.