Serial data from 1 output to1 PLC input

[CAI_Support]

Interesting.  You mentioned using one pair I/O to do the communication. If you use two pairs, that can work in much far range, for example A and B. Each time send out an "1", having A output high and B output low. When sending "0", reverse them.  With noise normally would make logic zero became one, or make logic one became zero, but it will not  be able to alter only one result to the downrange end, then at far end it can simply ignore the both ones and both zeros reading. 

 

[rossw]

Interesting.  You mentioned using one pair I/O to do the communication. If you use two pairs, that can work in much far range, for example A and B. Each time send out an "1", having A output high and B output low. When sending "0", reverse them.  With noise normally would make logic zero became one, or make logic one became zero, but it will not  be able to alter only one result to the downrange end, then at far end it can simply ignore the both ones and both zeros reading. 

 
Yes, but you've missed several of the key points about my 2-wire system.
 
1. It provides 24V at 2 amps for each downrange node to drive the actuator
2. It provides the downrange power to maintain the processors (one at each tracker) so they can listen for commands etc
3. It provides sufficient power to keep even the non-participating nodes alive.
 
Because of the low impeadance drive, I do not expect to have too much problem with the distances I expect it to operate over.

 

[todster]

View attachment SLC5_04-1-3-25.pdf

This looks like an engineering marvel, using I/O line to implement an AB PLC to WebControl PLC communication, Wow!

That's where a serial port would be nice. No engineering to it. I owe most of the credit for it to Ross. His ideas and inspiration went a long ways. This was more of a headbangers ball. I learned alot and still have so much more to learn. got a bald spot now as well.
The scan operation between the 2 as well as the difference in priority for timers was frustrating. I wanted a single wire but the timings got out of synch to easy. I'm passing 32 16bit words and placing them into 32 files with 256 words per file. This allows me to time stamp and then average out things if I want to track highs or lows. With the webset feature I can capture multiple boards with 1 central board.
I like Ross' 2 wire set up. If power over ethernet is POe then this must be what they call POS?   
 
Rung 18 and 24 are examples of the indirect addressing and how much code it saved me.View attachment SLC5_04-1-3-25.pdf
There is a lot of code there that is not used because it was for testing.