Sd - stop deceleration – ElmoMC SimplIQ Digital Servo Drives-Bell Command Reference User Manual
Page 160

SD - Stop Deceleration
Purpose:
Defines the deceleration in counts/second
2
used to stop motion in case of emergency.
In addition, SD defines the acceleration limit for the combination of software and
external reference commands.
Position-controlled motions cannot be stopped abruptly, because:
The discontinuity in the reference speed may produce position errors in excess of
ER[3]. This cuts the motor drive to freewheeling, which may be a safety problem with
high inertia or fast-moving loads.
If the maximum allowed acceleration value (GS[9]) is not correctly set, generating a
large position error can destabilize the position controller.
The SD parameter must be defined as the largest deceleration in which the motor can
accelerate/decelerate to the load.
The SD acceleration is applied in the following cases:
An ST command or hardware stop command (refer to the
IL[N]
command).
Data underflow in a PT or PVT motion.
Detection of a limit switch or an abort switch.
Attributes:
Type: Parameter,
Integer
Source:
Program, RS-232, CANopen
Restrictions: MO=0
Default value:
1,000,000,000 (RS), Non-volatile
Range:
Stop deceleration range
Unit modes:
UM=2, 3, 4, 5
Activation: MO=1
SimplIQ:
Modified (range extended)
See also:
AC
,
DC
,
ST
Application notes:
The Position Reference Generator
Unit mode 2: Speed control
SimplIQ for Steppers Command Reference Manual
Alphabetical Listing
MAN-STECR (Ver. 1.1)
152