If you haven't done that already you should download the datalist manual from here.

You can send a sysex message (BULK REQUEST) to the CS, and it will return a message containing all current parameter values. (BULK DUMP)
It's also possible to send a message that will ask for the setting of one parameter remotely, without the need to move a slider.

It's described in the datalist manual. I used the manual to develop my Reface DX/CS/CP/YC editor panels for Ctrlr.

For example:
To request the current voice parameter data from your Reface CS you need to use this SysEx request:

[code type=markup]
F0 43 2n 7F 1C 03 0E 0F 00 F7
[/code] (hexadecimal values, where n is a midichannel value between 0 and F)

The format of the returned SysEx dump with all values is described in detail in the datalist manual.

Thanks Martin. As you mentioned, I tried following code snippet

var method:MIDICompletionProc = MyMIDIReadDumpBlock //global function
let buffer:UnsafePointer = UnsafePointer([0xF0,0x43,0x20,0x7F,0x1C,0x03,0x0E,0x0F,0x00,0xF7])
var sendRequest = MIDISysexSendRequest(destination: self.virtualDestinationEndpointRef,
data: buffer,
bytesToSend: 10,
complete: false,
reserved: (0, 0, 0),
completionProc: method,
completionRefCon: UnsafeMutableRawPointer(&method))
MIDISendSysex(&sendRequest);

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
In this case my callback completionProc called but MidiReadBlock not invoked. Because of which I am not able to get the message event. There may be error in buffer values or other parameters.

Sorry, I'm afraid I don't know anything about coremidi programming.

Hi Martin,
I have following queries

Q1: If I want to get the state of control "LFO ASSIGN", can I use PARAMETER REQUEST with following format
[0xF0,0x43,0x30,0x7F,0x1C,0x03,0x30,0x00,0x02,0xF7]

The basic difference I found in Parameter Request and Bulk Dump is the third parameter 3n (Parameter), 2n (Dump Request).

Q2: What value passed for "n". I passed 0,1,2. Is there any way to get the channel number.

Q1: If I want to get the state of control "LFO ASSIGN", can I use PARAMETER REQUEST with following format
[0xF0,0x43,0x30,0x7F,0x1C,0x03,0x30,0x00,0x02,0xF7]

Looks OK to me on paper. I cannot test, since I don't own a Reface CS though

The basic difference I found in Parameter Request and Bulk Dump is the third parameter 3n (Parameter), 2n (Dump Request).

Correct.

Q2: What value passed for "n". I passed 0,1,2. Is there any way to get the channel number.

I would try 0. To change the MIDI channels you have to do some magick that can be found in the manual. Something like " while holding this and that key turn on the power". I think also firmware 1.30 is required for that but I'm not sure. The Reface DX has a menu function for it.

There is a way to get the channel number ... if you already know what the channel number is 😮