如何将param对象传递给d3.json？

My existing extJS code passes readData.php a param object

params: {
            start: 0,
            limit: 1000,
            proc_nm: 'sel_bkng_srch',
            srchStrng: '',
            parms: [[dnStrng,1],[mtStrng,1],[dtFromStrng,1],[dtToStrng,1]],
            connId: 'AW'
        }

so it can call a stored procedure which I want to share with d3. After lots of attempts, latest is:

d3.json("php/readData.php")
        .header("params", "params: {start: 0,limit: 1000,proc_nm: 'sel_bkng_srch',srchStrng: '',parms: [1,1],[2,1],[3,1],[4,1]],connId: 'AW'}")
        .get(function(error, data) {
            console.log('readData: ', error) ;                
        });

I do not have the syntax correct to pass the object with d3.json. Everything else is functional I think - php gets called, returns an empty success object (php code needs looking at here) which is picked up back in d3. tia.