To start, you should use the $READ_LKCMM_CFG technique and use the same LKCMM.CFG file that LK uses to maintain the machine since the parameters probably already have updated values. LK systems vary considerably, and no one setup of the interface runs them all.
If the $READ_LKCMM_CFG technique does not produce a result that works, use a full version of the DOWNL.OAD file instead. Try to set the NewInit entry to True first. If that is not successful, try to set NewInit to False. You may need to adjust the parameters to match what appears in LKCMM.CFG.
The parameter names in LKCMM.CFG are the same as the ones that are used in STARTUP files. The comments in the sample files in this documentation explain the meanings of these parameters. They are also shown below, with some real-world values from an old machine.
ACCB 400 50 2000 Backoff accel (m/min/min)
ACCM 600 50 2000 Max accel (m/min/min)
ACCV 500 10 500 Vector accel (m/min/min)
IFQTIM 99 0 99 Interface quiet time (secs)
LACCM 2000 50 2000 Legal acceleration (m/min/min)
PDAMP -1 -1 0 TP7 damping -1=on (Renishaw PICS interface),0=off (LK probe interface)
SBAK 1.5 .5 20 Backoff (mm)
SCVEL .2 0 1 Scan vel
SERL .5 .01 1 Position error limit (after fine pos command, mm)
SRLIM 10 1 20 Reset overtravel limit
SSBAK 5 0 10 Scanning backoff
STOT 10 1 100 Overtravel
STUT 10 1 20 Undertravel
TPLON 0 -1 0 Touch probe limited 'on' flag (-1=probe not active, 0=probe active)
VELB 8 .5 10 Backoff vel (m/min)
VELM 3 .5 10 Max vel (m/min)
VELT .15 .15 1 Touch vel (m/min)
VELV 5 1 5 Vector Vel (m/min)
VELVR 1 .5 10 SLOW VELOCITY (M/MIN)