Good day

I have programmed the digital output to be OFF2 active. My lecturer wants me to indicate that OFF2 is active by connecting a LED to the output.

I was thinking of connecting a current limiting resistor to the output(DOUT+ and DOUT-) and then the led.

or should i use something else.

Please help

Schematic would be great

bluerain23

Good day

I have programmed the digital output to be OFF2 active. My lecturer wants me to indicate that OFF2 is active by connecting a LED to the output.

I was thinking of connecting a current limiting resistor to the output(DOUT+ and DOUT-) and then the led.

or should i use something else.

Please help

Schematic would be great

 Hello again,

Put P0731 = 6 , then DOUT will be activated when OFF2 is active.

See this picture for parameter adjustment.

And here's the schematic.

You can wire it to a relay and then connect the aux. contact of the relay to a lamp or led.

I have already programmed that part the only problem is the circuitry for the LED to  DOUT. i have to connect an LED to DOUT to show that OFF2 is active.

So should i connect a current limiting resistor to the DOUT+ then the LED to the DOUT-, or should i use a different circuit

bluerain23

I have already programmed that part the only problem is the circuitry for the LED to  DOUT. i have to connect an LED to DOUT to show that OFF2 is active.

So should i connect a current limiting resistor to the DOUT+ then the LED to the DOUT-, or should i use a different circuit

 What's the voltage rating of your indication LED or Lamp?

it has a max current of 20mA, and max voltage 3.2V

bluerain23

it has a max current of 20mA, and max voltage 3.2V

 Ok. If you have 3.2 Volt. Power Supply,  then you don't need to connect a resistance. 

If you have Power Supply with output Voltage greater than 3.2V, then you will need to make voltage divider by connecting a series resistance.  Its value can be calculated based on the output Voltage of power supply. 

Given your non controls standard voltage of 3V for the LED, I would use a relay driven by OFF2's Dout.  When OFF2 is happy, make the relay happy and use a NO contact to drive the LED with a 3V power supply (or voltage divider as was suggested).

Using the external relay will make you much happier.

You can probably still make it work without a relay, but let's face it, if you do it wrong and blow up your drive, you will be very unhappy.  If you do it wrong with a relay, you fix it, and pop in another relay and you are the hero. 

bluerain23

I have already programmed that part the only problem is the circuitry for the LED to  DOUT. i have to connect an LED to DOUT to show that OFF2 is active.

So should i connect a current limiting resistor to the DOUT+ then the LED to the DOUT-, or should i use a different circuit

New question published by bluerain23 is split to a separate thread with the subject Control the speed of Sinamic G110 with S7-300.

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New question published by bluerain23 is split to a separate thread with the subject Help with programming a S7-300 PLC with the step 7 V5.5.

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