How do I change from AT to Multipoint mode?

The procedure for changing from AT to Multipoint mode is as follows:

Send command “ATS126?”.

The response will be a 4 digit hexadecimal number in the form $abcd.

Calculate the 1’s complement of the returned value. For example, the value $18AB will be converted to $E754. This can also be achieved by using the enclosed “1sComplement.exe” application. Run the program and simply enter the returned value from step 3 and press Calculate to achieve the required conversion.

Send command ATS126=$wxyz where wxyz is the 1’s complemented value.

Send command ATS127=$200.

Power cycle and your module is in multipoint mode.