Analog Inputs

Dears

I am making a programme with siemens Mini Plc logo 236 CR. Can any body advise me , How can I connect analog inputs like speedmonitors.
How I can connect the three wires of speedmonitor to the analog input.

I didn't know they already had a Logo! with an analog input. As far as I know Logo! is strictly digital.

Kind regards,

Most LOGO are digital but Siemens recently released models with analog inputs.

For more details, go to:

https://mall.ad.siemens.com/WW/gues...353-926-925-924-1-1448-1450-1451-&jumpto=1451

OK Guest, my mistake. After re-reading the manual (yes, some of us really do that - but only if we need to) I found indeed that two of the 8 inputs on a basic Logo (e.g. Logo!230RC) can be used as analog inputs with a range 0-10V.

If your speedmonitor has three wires, I guess the most probable configuration would be for one wire to be connected to the positive pole of a 10Vdc power source, one wire to be connected to both the 0V pole of the power source and to the common of the Logo, and one wire to be connected to the analog input. Should be fairly basic electronics.

Kind regards,

I found indeed that two of the 8 inputs on a basic Logo (e.g. Logo!230RC) can be used as analog inputs with a range 0-10V.

Click to expand...

I would assume that as well, if the speed monitor is a voltage sourcing device. It must be a voltage device to work with direct connection to the input. If it is a current output device a simple resister placed across the input to ground would act as the "voltage" source. If it is a current "loop" powered device the same can be true of the resister but there would be a little more to the wiring.

Use Ohms law to determine the value of the resister. You may also check the manufacturers specifications, they may provide some connection tips.

But without any more info on the device we cannot help you any further.

bitmore

hi
please Help me
How do I convert the sensor from 0 to 60 bar to 4 to 20 mA in a miniplc logo v8?

Hi,

I normally use the 'analogue amplifier' instruction to give you your scaling. See attached screenshots of a typical analogue conversion. I also normally add some sampling control and an alarm flag per analogue.

(Might want to start a new thread in future as this one's pretty old!!)

Hope this helps,

Rob