Convert decimal to hexadecimal from web browser

[kcks66]

Hi Mikhail,

I connected an inverter and I want to read its running output frequency and write command from web browser to change its output frequency.

I managed to read its running output frequency. I faced challenge when I want to write command into the inverter from web browser.

The inverter accept hexadecimal command to run with prefer output frequency. Below is the screenshot from communicator device which I could write command successfully in hexadecimal format.

https://ibb.co/LRdn8fS

0001 refer to run
0BB8 refer to decimal 3000 (30Hz)

I could use web browser to enter 00010BB8 and write successfully into the inverter.

https://ibb.co/4gSjNCk

I wish to enter decimal number example 30 in web browser and how to convert the 30 decimal number from web browser into 00010BB8 hexadecimal at the output channel before send to the inverter?

Looking forward from your advice. Thank you.

[manjey73]

You need to use the formula in the control channel that will send the generated CmdData

[kcks66]

Hi manjey73,

You meant write a scripts to convert decimal numbers to hexadecimal numbers in the output channel?

I am weak in scripting. Any idea how to do it?

Thank you.

[Mikhail]

Hi,
What is the current formula of the output channel?

[kcks66]

Hi Mikhail,

Currently output channel has no any formula.

[manjey73]

public byte[] NewFreq()
{
byte[] freq = BitConverter.GetBytes)(uint)Cmd*100);
return new byte[] { 0x00, 0x01, freq[1], freq[0])
}

I haven’t checked, but something like this

[zzz]

from webbrowers to VFD sounds a bad idea, there should be at least a middle agent to validate the data or access control etc…

[kcks66]

Hi manjey73,

I got error message from SCADA Server:

Error calculating standard command value for the output channel 20032: Unable to cast object of type ‘System.Byte[]’ to type ‘System.IConvertible’.
Command is canceled

My output channel formula:

public byte[] NewFreq()
{
byte[] freq = BitConverter.GetBytes((uint)Cmd*100);
return new byte[] { 0x00, 0x01, freq[1], freq[0]};
}

Pls advice and thank you.

[manjey73]

Formula

Script in channel

result on web

For me, the formula does not cause errors during compilation. And the result of sending from the Web is shown below. It may be necessary to rearrange the bytes in the formula. Well, configure the command in the Modbus template as multiple for several registers in addition to the other channels.

[manjey73]

Yes, there is another nuance, in the formula it is necessary to additionally convert the number to HEX. We need to think about how to do this… Just using BitConverter is not enough for this

[manjey73]

| 31.07.2023 08:59:05 | Code=freq, Data=00010BB8 |

Enter 30 in Web.
Although no, it seems to be enough, I entered 30 into the Web and received the following data in the sent command.

[manjey73]

Is this your Modbus device ?

[kcks66]

Hi manjey73,

| 31.07.2023 08:59:05 | Code=freq, Data=00010BB8 |

Enter 30 in Web.
Although no, it seems to be enough, I entered 30 into the Web and received the following data in the sent command.

YES, this is what I need.

I need to start from beginning step by step follow your instructions.

The formula below is correct?

public byte[] NewFreq()
{
byte[] freq = BitConverter.GetBytes((uint)Cmd*100);
return new byte[] {0x00, 0x01, freq[1], freq[0]};
}

[kcks66]

Hi manjey73,

Next is my device template:

https://ibb.co/gvcV15y

Follow by my output channel:

https://ibb.co/PDzX6hh

[kcks66]

Hi manjey73,

I entered 30 in web browser:

https://ibb.co/yfZv0Tn

But error message occur:

https://ibb.co/Dtx5cVZ

What have I missed out?

[Author]

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