
B–64113EN–1/01
14. MEASUREMENT
959
P : Distance to be measured [mm/inch]
Q : Servo delay [mm/inch]
Under the conditions shown above, the NC calculates the following
equation using parameter SEA (bit 0 of parameter No. 6201) or SEB (bit
1 of parameter No. 6201):
P = Pnc – Q
For type A (SEA bit 0 of parameter No. 6201 is “1”), the deviation is
calculated by:
Q = Fm 1/60 (a Tc/1000 + Ts/1000)
where
Fm : Feedrate [mm/min or inch/min]
Tc : Cutting time constant [msec]
Parameter No. 1622: Exponential acceleration/deceleration
Parameter No. 1628: Linear acceleration/deceleration after
interpolation
If parameter SKF (bit 7 of parameter No. 6200) = 0, Tc = 0.
Ts : Servo time constant [msec]
Assuming that the loop gain (parameter No. 1825) is G (unit: 1/s):
Ts = 1000/G
α : = 1 Exponential acceleration/deceleration
= 1/2 Linear acceleration/deceleration after interpolation
NOTE
For type A (parameter SEA (No. 6201 #0)=1), the skip signal
must be turned on when the tool moves at constant
feedrate.