Galil DMC-13X8 High Speed Position Capture (The Latch Function)

Chapter 6 Programming Motion • 104 USER MANUAL
Command Summary - Homing Operation
COMMAND DESCRIPTION
FE XYZW Find Edge Routine. This routine monitors the Home Input
FI XYZW Find Index Routine - This routine monitors the Index Input
HM XYZW Home Routine - This routine combines FE and FI as Described Above
SC XYZW Stop Code
TS XYZW Tell Status of Switches and Inputs
Operand Summary - Homing Operation
OPERAND DESCRIPTION
_HMx Contains the value of the state of the Home Input
_SCx Contains stop code
_TSx Contains status of switches and inputs
High Speed Position Capture (The Latch Function)
Often it is desirable to capture the position precisely for registration applications. The DMC-13X8
provides a position latch feature. This feature allows the position of the main or auxiliary encoders of
X,Y,Z or W to be captured within 25 microseconds of an external low input signal. The general inputs
1 through 4 correspond to each axis.
1 through 4:
IN1 X-axis latch
IN2 Y-axis latch
IN3 Z-axis latch
IN4 W-axis latch
Note: To insure a position capture within 25 microseconds, the input signal must be a transition from
high to low.
The DMC-13X8 software commands, AL and RL, are used to arm the latch and report the latched
position. The steps to use the latch are as follows:
1. Give the AL XYZW command to arm the latch for the main encoder and ALSXSYSZSW
for the auxiliary encoders.
2. Test to see if the latch has occurred (Input goes low) by using the _AL X or Y or Z or W
command. Example, V1=_ALX returns the state of the X latch into V1. V1 is 1 if the
latch has not occurred.
3. After the latch has occurred, read the captured po sition with the RL XYZW command or
_RL XYZW.
Note: The latch must be re-armed after each latching event.
Example:
#Latch Latch program
JG,5000 Jog Y