ElmoMC SimplIQ Command Reference - Manual (Page 175)

XM[N] - X Modulo
Purpose:
Specifies the counting range for the main feedback, which is [XM[1]…XM[2]-1].
The position of the main feedback is always counted cyclically. This means that after the
position is counted to its maximum value, the next position count will reset the position
counter back to its minimum value. The speed reading is not affected by the position
jump. For example: If XM[1]=-5 and XM[2]=5, the main position is counted in a cycle
length of 10. The main position will always be in the range [-5…4]. If the main feedback
rotates in the positive direction, the main position count will proceed from 0, 1, 2, 3, 4 to -
5, -4, -3, -2, -1, 0, 1 . . . and so on.
If XM[N] is nonzero with UM=5, the controlled motor position will count cyclically. All
motion trajectories will go the short way. For example: If XM[1]=-512, XM[2]=512, the
initial position is PX=-500 and the target absolute position is PA=500, the PTP trajectory
will travel through -500…-512, 511…500 to a total distance of 23 counts.
The cycle length must be positive (XM[2] > XM[1]) and (XM[2] - XM[1]) must be an even
number. XM[N] values violating the above conditions will be accepted, but not activated.
Until XM[N] can be activated, the motor cannot be started and the parameters cannot be
saved in the flash memory (the SV command will not work).
Notes:
ƒ If XM[1] or XM[2] is set so that XM[2] > XM[1] but PX is out of the range
[XM[1]…XM[2]], PX will be set to range by taking modulo:
PX = (PX - XM[1]) mod (XM[2] - XM[1]) + XM[1]
ƒ If a homing process requests a PX value setting out of the range [XM[1]…XM[2]],
the request will be ignored and PX will not change.
ƒ If the XM[N] value is selected low and the main speed is too high, more than one
full revolution of the main counter may elapse within a single sampling time. This
will cause the main position counter to behave unpredictably.
ƒ XM[N] cannot be modified while the homing sequence is active (HM[1] > 0).
Attributes: Type: Parameter, Integer
Source: Program, RS-232, CANopen
Restrictions: MO=0
MO=1 and SV cannot be used before XM[2]
and XM[1] are activated (see “Activation”
below)
Default values: XM[1]=-10
9 , XM[2]=10 9 (RS), Non-volatile
Range: [-10 9 …10 9 ]
Unit modes: All
Activation:
XM[2] > XM[1] and XM[2] - XM[1] is an even
number
See also:
YM[N] , PX
SimplIQ Command Reference Manual Alphabetical Listing
MAN-SIMCR (Ver. 4.5)
3-162