Hello! I'm trying to figure out how to connect a Siemens LOGO! smart relay to an Incremental Encoder.

The Incremental encoder is this: ES5-10CN8940 (Delta Rotary Incremental Encoder).

This is only for testing purposes. I have already used S7-1200 for an encoder, and thanks to your help (experts) it worked as it should (posted in another forum).

Now, I have read some forums, and viewed the help in LOGO! Soft Comfort, and saw that indeed the inputs I3, I4, I5 and I6 are used for encoder high speed inputs to up to 5Khz if directly connected to the counter function block. 

So, just to test it, I put in a very simple program. I3 connected to a counter connected to an open connector (X1). I set the ON limit to be 1000. (I'm using LOGO OBA6 by the way).

Now, I gave the encoder a 24V power (externally of course) connected to its brown and blue wires. Afterwards, I have connected the black wire to I3. Finally, I ran the online simulation and tested it by monitoring. But, it was not counting or doing anything. I do not know if LOGO! is different, it just didn't accept it the input. I kept rotating (both slow and fast by hand) but it did not count. 

Did I do anything wrong in the connection mayhaps? Please provide with as much as information as you like. 

NOTE!!!: I have tried the offline simulation, and it worked perfectly, meaning the code is supposedly correct, no? Thank you in advance :)

Online simulation is not possible with LOGOSoft.

You can look at the running programming in the LOGO when your programm on the computer is exactly the programm on the Logo. Notice that online look at the working programm is verry slow, so you have an encoder you must turn it very slow. iF you turn to fast you cant see the right working of the input, but the value of the connected Block become right on your PC screen, but a little late.

Also in simulationmode on your PC screen (with no LOGO connected) is not verry quick. De real LOGO is much faster than simulation.

Oh..    I read ......

Open Collectir output means that you cant directy it to the LOGO. The logo must havenon + Input, so you must use an open emmitir output of your ecoder, 

You can also use an Pull-Up resitor (about 1 kOhm) between the + and te Digital input.  So your encoder can "sink" the signals. Try it!

Pyrus

Now, I gave the encoder a 24V power (externally of course) connected to its brown and blue wires. Afterwards, I have connected the black wire to I3. Finally, I ran the online simulation and tested it by monitoring. But, it was not counting or doing anything. I do not know if LOGO! is different, it just didn't accept it the input. I kept rotating (both slow and fast by hand) but it did not count.

If the supply voltage for the encoder is not the same as for the Logo, you need the M (0V) connect of both voltages together or as a supply voltage for the encoder is the same as for the Logo.

Of course the power supply is the same, otherwise the encoder will not work properly with the LOGO!.

I put a 10 kohm pull-up resistor, and it worked perfectly!!!!! THANK YOU !!!!!!

Pyrus

Now, I gave the encoder a 24V power (externally of course) connected to its brown and blue wires.

What did you mean because then with this sentence?
Especially "external course".

Pyrus

Now, I have read some forums, and viewed the help in LOGO! Soft Comfort, and saw that indeed the inputs I3, I4, I5 and I6 are used for encoder high speed inputs to up to 5Khz if directly connected to the counter function block. 

Hi Pyrus.

You make no mention of which LOGO you downloaded to for the online test. You must use a transistor type (24V) LOGO and not the relay type.

Do know the special input must be connected directly to the count pin of the counter. Only then will the 5khz be possible.

The input on-off thresholds on the LOGO is different than that of the S7-1200. Check with a voltmeter what the voltages are that you get from the encoder. A 10kohm pull-up resistor sounds high. 1.2kohm (0.5W) resistor is closer to what I expect.

I assume you are using only one phase........ which are you using? Again test with the voltmeter to see if the voltages change (if it is not the one you know is working).

Maybe share also the program segment you are testing and a sketch of the electrical connections... just as a double check

William_B

You make no mention of which LOGO you downloaded to for the online test. You must use a transistor type (24V) LOGO and not the relay type.

Why this?

The data of the digital inputs are the same, regardless of whether transistor or relay variant.

ixo65

William_B

You make no mention of which LOGO you downloaded to for the online test. You must use a transistor type (24V) LOGO and not the relay type.

Why this?

The data of the digital inputs are the same, regardless of whether transistor or relay variant.

I am so glad you mention this.
Just two weeks ago I checked the LOGO manual on this for the OBA8:

(information extracted from Appendix A of LOGO! Manual, 06/2014, A5E33039675)

..while..

Your thoughts?
w

The 24V Logos (0BA8) are available as:
- 24CE and 24CEo (transistor outputs), 24VDC.
- 12/24RCE and 12/24RCEo (relay outputs), 12/24VDC.

These logos the data of the digital inputs are identical, 4 Hz for normal input and 5 kHz for fast counting input.

Then there is this:
- 24RCE and 24RCEo (relay outputs), 24VAC / DC

This does not fast count inputs, because you can also be operated with 24VAC.

ixo65

The 24V Logos (0BA8) are available as:
- 24CE and 24CEo (transistor outputs), 24VDC.
- 12/ 4RCE and 12/24RCEo (relay outputs), 12/24VDC.

These logos the data of the digital inputs are identical, 4 Hz for normal input and 5 kHz for fast counting input.

Then there is this:
- 24RCE and 24RCEo (relay outputs), 24VAC / DC

This does not fast count inputs, because you can also be operated with 24VAC.

aaah yes now I remember....
it is about the (only) DC variant not the relay variant!!
Thank you for clearing that up.

The specifications on that....

Our factory bought the "24RCE" type which was wrong for the application.
I focussed on the wrong detail (relay) but we had to change in any case.