I am tying to interface a Logo!8 to the following signals.

- When digital input is low analogue input is temperature reading number 1.

- When digital input is high analogue input is temperature reading number 2.

How can I demux the analogue inputs to individual values of temperature readings 1 & 2 for further Logo processing ?

Some form of analogue latch is required ?

A simple example is in the attachment

No comment in the programm, you must self make the right settings in the blocks

Sorry, but that solution is not quite it. Thank you.

Maybe I didn't explain fully.

When I1 is low, AI1 is the temperature sensor 1 value.

When I1 is high, AI1 is the temperature sensor 2 value.

Both input analogue values come in via the same analogue input AI1 with I1 determining if temperature 1 or temperature 2 reading.

I need to de-mux the AI1 input to get temperature 1 and temperature 2 values so that further Logo analogue processing can be done.

Sorry for the mis-unterstanding

So better?

Thanks.

Still not quite right. There needs to be some analogue "hold/store" feature to say store temperature 1 for processing, whilst the control input I1 is high (and store temperature 2 when I1 is low).

Your solution, unfortunately outputs 0 to temperature 1 when I1 is high, there needs to be a latch/store of temperature 1 value (and temperature 2).

I need access to steady state values for temperature 1 and temperature 2 for further processing.

ian_m42

Thanks.

Still not quite right. There needs to be some analogue "hold/store" feature to say store temperature 

 Thats not what you asked first...

But so better?

Only when power down or LOGO goes STOP  the value is lost!

Brilliant. Thank you.

I hadn't seen the 'When En="0", output is:' ---> Last Value setting in the "Mathematical block" settings.

It therefore acts as an analog latch holding the last value. Just what I need.

New question published by Dicky is split to a separate thread with the subject Implement Analog Demux - Need to store the daily count value into analog flag.

Best regards
Jen_Moderator