Could you do a split?
var ledResponse = "psen 1,1,1,344,2055,8156,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1";
var ledResponseArray = ledResponse.split(",",6); // ignore rest of string after 6 entries
var value1 = ledResponseArray[3];
var value2 = ledResponseArray[4];
var value3 = ledResponseArray[5];
#DashBoard