# Read Coil Analogic Output M103

• I'm using Unipi Neuron M103 and i can't figured out what Coil can i use for using Analogic Output.

And how can I send what voltage need to be used?

• Hello @mohamed-dounnani,
it is unclear, what type of software you use. Let's assume you use pure Modbus, please correct me if you use Mervis or Evok.

You can find complete information about available coils and registers in the Modbus Registers Map of your unit. Unfortunately, no register contains the calculated voltage and you need to calculate the real value in your program. The calculation formula, which you can find in the Neuron Technical Documentation looks like this:

So in order to calculate the values, you need to poll 5 registers:

• Vref (register 1009)
• VrefInt (register 5)
• AI1vdev (AI 1 Voltage Deviation, register 1025)
• AI1voffset (AI 1 Voltage Offset, register 1026)

Regards,
Martin

• This formula is for Analog Input it's correct? I need to use analog output's formula

• @mohamed-dounnani Oh sorry, I overlooked it... Anyway, you can find the formula for analog output in the Neuron Technical Documentation I posted above. The system is practically the same, just with different registers and different formula.

Martin

• What is meant by Datatype Word?
So basically when I have the value from this formula I need to put it on Analog Output address?

• Hello @mohamed-dounnani,
the datatype word defines integer number in the range of 0-65535. And you need to save the calculated value into the "Analog Output 1" register.

• Ok thank you very much!

• So, If i need to turn off a 0-10v device i need to put 0 in Vdesired ?

• @mohamed-dounnani The device (analog output) cannot be turned off, but if you want it to output 0V, then save the value 0 to the "Analog Output 1" register

• How can i Turn Luminosity to 0 or simulate that is off? Because if I put 0V, decrease luminosity but not completely
There is any way to do accomplish that?

• @mohamed-dounnani Can you please describe what are you trying to achieve? So far we were discussing analog outputs, which I am unable to connect with luminosity. A schematics of your setup or list of devices which you want control would be heplful. Thank you!

• I have a 0-10V Led. I need to be able to turn it Off and On with a certain luminosity. I choose a Vdesired for example 5V and the luminosity decrease, now i need to turn it off when necessary. But when I insert a 0V in Vdesired luminosity decrease at 10% about but never turn off.

• @mohamed-dounnani You can simply verify the functionality with multimeter by measuring the output voltage between AO and AGND. With register "Analog Output 1" = 0 the output voltage should be 0V.

• @martin-kudláček "With register "Analog Output 1" = 0 the output voltage should be 0V". I do that but still the light is on.

"You can simply verify the functionality with multimeter by measuring the output voltage between AO and AGND. " What I accomplish with this operation?

• @mohamed-dounnani You will verify, that the data you set in the Modbus registers really do what you are intending to do.

I guess you use some LED 0-10V dimmer, similar to this one:

If the D- and D+ are unconnected or shorted (connected together) the LED should be off. Is this happening to you?

• They are connected. I can't misure now the V in output, there is a way to be able to turn led completely off?

• @mohamed-dounnani
Basically there can be two things wrong in your setup and in order to help you I need you to test them separately.

1. Verify the output voltage
• Disconnect everything from the AO and AGND
• connect a voltmeter (or multimeter set to DC voltage measurement) between AO and AGND (positive / red test lead to AO, negative / black test lead to AGND)
• set the desired voltage via Modbus registers and verify the actual output voltage
• set the voltage to 0V via Modbus registers and verify that the output voltage is 0V
1. Verify the functionality of the LED dimmer
• connect the LED to the dimmer
• connect the power supply to the dimmer
• leave the 0-10V input unconnected
• the LED should be off.

Please proceed with both suggestions and get back to me with the result. Otherwise it is almost impossible to help you.

Thank you for understanding,
Martin

• "Verify the functionality of the LED dimmer
connect the LED to the dimmer
connect the power supply to the dimmer
leave the 0-10V input unconnected
the LED should be off."

I leave the 0-10V input unconnected from unipi and led are On like 100% Luminosity.

"Verify the output voltage
Disconnect everything from the AO and AGND
connect a voltmeter (or multimeter set to DC voltage measurement) between AO and AGND (positive / red test lead to AO, negative / black test lead to AGND)
set the desired voltage via Modbus registers and verify the actual output voltage
set the voltage to 0V via Modbus registers and verify that the output voltage is 0V"

When I set 0V via Modbus multimeter reveals like 1.066 Volt and not 0 volt.

• Ok @mohamed-dounnani, now we are getting somewhere!:)

For the first part (verifying the output voltage), did you try to set the voltage to e.g. 5 volts and measured the actual output as well? What was the result? I need to be extra sure, that your way of saving data into the Modbus registers really works. It's not that I don't trust you, but it isn't really straightforward:)

Thanks!
Martin

• If i set 6 Volt the result is 2294.784382284382