Analogue Input Type not correct?

knebb

Hi,

on my M103 (old model) I have attached to my analogue input a sensor which delivers 0-10V.
I can read this voltage through modbus. So far, everything is fine.

I am just wondering why it works ;)

Register 1024 is supposed to configure the type of measurement:

However, register 1024 always shows "0" for me, while the input rating shows the right voltage.
My code:

union   {
        uint16_t word[2];
        uint32_t dword;
        float flt;
} wert = 0;
err =  modbus_read_registers(connection, 1024 , 1, &wert.word[0]);
printf("[read_ai] Wert: %d",wert.dword);

// Now read the voltage:
err =  modbus_read_registers(connection, 3002 , 2, &wert.word[0]);
printf("[read_ai] wert.flt: %5.2f",wert.flt);

Output is:

[read_ai] Wert: 0
[read_ai] wert.flt: 3.00

So value 0 mean "disabled". But it still reads the voltage. Shouldn't it be at "1" for the default mode of measuring voltage?

/KNEBB

cleve

Hello @knebb,
what is your OS and firmware version?

knebb

@cleve

Neuron M103 (the old one, not the current) which is still running with Raspbian 10/ buster.

How do I get the information about the firmware?

(BTW: I tried to upgrade to latest Raspbian, but failed)