ElmoMC SimplIQ Digital Servo Drives-Bell Command Reference - Manual (Page 173)

TT[N] – Motion Processor Sampling Time
Purpose:
This command sets the sampling time of the motion controller.
TT[1]: Sampling time of the motion processor, µsec.
TT[1] is the sampling time of the current loop. The sampling time of the velocity
controller and of the position controller is two times TS. For example, if
TT[1]=40, the torque/commutation controller runs once every 40 microseconds, the
speed controller and the position controller executes every 80 microseconds.
For all unit modes, WS[28] and WS[55] give the actual sampling time of the speed and of
the position controllers
6 .
Notes:
When TT[1] is increased, the current loop gains must be revised in order to
prevent instability of the current loop, which may damage the drive and/or the
motor.
For > 1KW drives, the selection of TT[1] is a compromise between high servo
performance and switching losses in the drive. Lower TT[1] implies increase in
the available control bandwidth, but also implies increased switching rates of the
power stage, thus increased heating.
Attributes: Type: Parameter, Integer
Source: RS-232, CANopen
Restrictions: Motor off
Default values: 40 µsec
Index range: [1]
Range: [30..60]
Unit modes: All
Activation: Immediate
SimplIQ: New
command
Note: This command takes a few milliseconds to perform.
See also:
WS[N],WI[N]
Under most circumstances, this command is used only by the tuning environment.
Application note:
The motion processor
6 There are two readouts for the same thing since historically in SimpleIQ the sampling
times for speed and position were different.
SimplIQ for Steppers Command Reference Manual Alphabetical Listing
MAN-STECR (Ver. 1.1)
165