Topics created by CKB

Hi,

The best way to calibrate the AI on the Unipi 1.1 is to turn off the transformation for the AI, connect a voltage source with an output of exactly 10 VDC and look at the value on the AI in the Mervis IDE. Remember this value and then insert it as parameter X2 in the two-point linear transformation.

Set parameter Y2 to 10 if you want to get the voltage value directly, or set to 100 if you want to get the percentage value [%].

Set both parameters X1 and Y1 to 0.

In the attached picture you can be inspired by the settings for my Unipi 1.1.

Unipi11_AI_set.png

Have a nice day
Regards

Antonín Všetula,
Technican

Hello @CKB,
it is LM358 for amplification of the analog output.

Hi @CKB,
the Unipi Extensions are generic ModbusRTU slaves. Since they communicate over RS485 and Unipi 1.1 doesn't have any, you need to use USB/RS485 converter.

Best regards,
Martin

Hi @CKB,
the functionality has changed, and now you cannot define more than one task. But you can define more programs to run inside a single task.

Best regards,
Martin

Ahh, just found it - BD18 Bit Composition ! :)

@ckb

It can be theoretically connected to the UniPi 1.1, you will not get it working directly in the Mervis. Mervis doesn't have any support for custom I2C devices. You would have to write some I2C - Modbus bridge in Python for example.

Hi @ckb,
if you use Mervis on UniPi 1.1, then you have practically no other option other than to use ModbusTCP. On the RaspberryPi you can create a Python script utilizing the pymodbus library and program the logic in a way the DIs and ROs are mapped to the coils and AO/AI are mapped to registers.

Best regards,
Martin

@ckb the inverse behavior of AO was a bug and is now fixed. Since 0 is a default value, most users do not want a default 10V after startup of the application.

You would have to smoothen it in the SW - create your own function block which will add/deduct automatically every a part of the difference |current_voltage-target_voltage| every cycle(or every 0.1s). But honestly, this most probably will also cause visible steps in the dimming process.

@mdturnerphys Sure! We expect to release the new Mervis IDE and required tutorials on our new knowledge base this Friday.

The values look correct. You should be able to read the temperature in degrees Celsius from the "tmp_real" variable.

As the thermometer internally uses Celsius, any conversion to Fahrenheit must be done in your program. It is not possible to achieve more precision than given, as again the thermometer is designed to give output in fractions of degrees celsius.

@CKB If both UniPis are running Mervis, have them both in one project and use the SSCP protocol which is native protocol of Mervis. An example of this can be found at download section of Mervis.

Hi @CKB.

Have a look in the Mervis Help by pressing F1 to find Sendmail...

Hope this help.

@Giamba