help wanted encoder plc !!!!

[bernie_carlton]

Your first, with the pullups leaves only about 9 volts at the input terminal. Measure from Gnd to the input terminal to verify.

Your second drawing is hard to interpret.

With regard to your very first drawing. I assume that the grounds from the 5 volt supply and from the 12 volt supply are connected together. Remove GND from the C0 terminal. Instead attach +12 volts to that terminal. Remove any pullup resistors.

The inputs are designed to work with current flowing either way. The internal 1.8K resistance will limit the current.

I attached a revised version of your drawing.

 

[ALIMARY15]

Your first, with the pullups leaves only about 9 volts at the input terminal. Measure from Gnd to the input terminal to verify.

Your second drawing is hard to interpret.

With regard to your very first drawing. I assume that the grounds from the 5 volt supply and from the 12 volt supply are connected together. Remove GND from the C0 terminal. Instead attach +12 volts to that terminal. Remove any pullup resistors.

The inputs are designed to work with current flowing either way. The internal 1.8K resistance will limit the current.

I attached a revised version of your drawing.

thank you i checked your wiring diagram but the thing that is not clear to me is about the QA and QB 12 v signals that are from the uln2803.
the Uln2803 pins where i wire the 12 V supply are the same from which i take the signals Qa and QB to the inputs?
the Uln has only a two side pin interface.

 

[bernie_carlton]

Get out the ULN2803 data sheet and look at the schematic diagram.

The 12 volt supply wires to the COM pin (10) on the ULN2803. This provides protection to the outputs through the reverse biased diodes as well as a weak pull up. It does not actually power the circuitry. DC common is attached to the GND connection (9).

When connected as I mentioned the 'electron type' current flow for a given signal is from the GND connection through the Darlington transistor pair, out the output pin, into the input terminal of the DL06, through its internal opto-isolator's input and out the C0 pin to your 12 VDC positive side.

And, as mentioned before, if you can use a higher voltage, up to 24VDC, the signal would be better. The ULN2803 can take it.

 

[ALIMARY15]

Get out the ULN2803 data sheet and look at the schematic diagram.

The 12 volt supply wires to the COM pin (10) on the ULN2803. This provides protection to the outputs through the reverse biased diodes as well as a weak pull up. It does not actually power the circuitry. DC common is attached to the GND connection (9).

When connected as I mentioned the 'electron type' current flow for a given signal is from the GND connection through the Darlington transistor pair, out the output pin, into the input terminal of the DL06, through its internal opto-isolator's input and out the C0 pin to your 12 VDC positive side.

And, as mentioned before, if you can use a higher voltage, up to 24VDC, the signal would be better. The ULN2803 can take it.

thank you bernie im going to try this kind of wiring. so summing up,
i wire the 12 V to the COM of the ULN till the C0 of the plc. then the rest remain the same and without using pullup resistors i connect the QA AND QB of 12 V to the plc inputs.
I am gonna try to implement this and see if my ladder program going to work.

thank you so much for your explanations

 

[ALIMARY15]

Your first, with the pullups leaves only about 9 volts at the input terminal. Measure from Gnd to the input terminal to verify.

Your second drawing is hard to interpret.

With regard to your very first drawing. I assume that the grounds from the 5 volt supply and from the 12 volt supply are connected together. Remove GND from the C0 terminal. Instead attach +12 volts to that terminal. Remove any pullup resistors.

The inputs are designed to work with current flowing either way. The internal 1.8K resistance will limit the current.

I attached a revised version of your drawing.

Hello bernie,i have tried your wiring diagram and it works!!! now the counter counts and do its work!

I want to thank you for your precious help!!!

maria

 

[bernie_carlton]

I'm glad I could help.