Gemini GV6K and Gemini GT6K Programmer's Guide

Encoder-Based Stepper Operation (stepper only)
Encoder Resolution
When using an encoder in a stepper application, you may configure the following:
• Encoder resolution
• Stall Detection & Kill-on-Stall, Stall Deadband
• Encoder-based position reference and position capture
You must specify the encoder resolution with the ERES command.
Stall Detection & Kill-on-Stall
To detect stalls without
an encoder, refer to
Drive Stall Detection on
page 66.
The ESTALL1 command enables the drive to detect encoder-based stall conditions.
NOTE: Encoder count reference must be enabled (ENCCNT1) before stall detect (ESTALL)
can be used.
If used with Kill-on-Stall enabled (ESK1 command), the move in progress will be aborted upon
detecting a stall. If queried with the ER or the AS commands, the user may branch to any other
section of program when a stall is detected. Refer to the ER, and AS command descriptions in
the Gem6K Series Command Reference for more information.
Kill-on-Stall functions only if the stall detection is enabled (ESTALL1).
WARNING
Disabling the Kill-on-Stall function with the ESKØ command will allow the controller to finish
the move regardless of a stall detection, even if the load is jammed. This can potentially
damage user equipment and injure personnel.
Stall Deadband
Another encoder set-up parameter is the Stall Backlash Deadband (ESDB) command. This
command sets the number of commanded counts of error allowed, after a change in direction,
before a stall will be detected. This is useful for situations in which backlash in a system can
cause false stall situations.
Encoder Set Up Example
Examples for 4 Axes
(command line samples)
The example below illustrates the features discussed in the previous paragraphs. The DRES
statement defines the motor resolutions. The ERES statement defines the number of encoder
steps per encoder revolution. A standard 1000-line encoder is used that produces 4000
quadrature steps/rev. Encoder counting (ENCCNT), stall detect (ESTALL) and kill-on-stall
(ESK1) are enabled. If a stall is detected (more than 10 steps out without an encoder step
back), the motor's movement is killed. The ESDB statement defines the stall deadband.
DRES25000
ERES4000
ESK1
ENCCNT1
ESTALL1
ESDB0
; Set drive resolution
; Set encoder resolution
; Enable kill motion on stall
; Enable encoder counting (this is
; required for ESTALL to work)
; Enable stall detection
; Set stall deadband
84 Gem6K Series Programmer’s Guide