Yaskawa MP2000 Series: Built-in SVB or SVB-01 Motion Module - Manual (Page 430)

11.4 Modal Latch Function
11-15
Utility Functions
11.4 Modal Latch Function
The Modal Latch function can be executed to latch a position independently from the motion command being executed
as long as the motion command being executed is not a motion command with latch function such as EX_POSING,
ZRET, and LATCH.
If a motion command with latch function, such as EX_POSING, ZRET, and LATCH, is executed while the modal latch
function is being executed, the motion command has priority over the modal latch function, therefore, the motion
command will be executed first.
Latch Request
A latch request is sent at the moment the Latch Detection Demand bit (setting parameter OW 00, bit 4) turns ON
from OFF.
When the latch is completed, the Latch Complete bit (monitoring parameter IW
0C, bit 2) will turn ON.
The latched position will be written in the monitoring parameter IL 18 Machine Coordinate System Latch Position
(LPOS).
Cancelling Latch Request
Set the Latch Detection Demand (setting parameter OW 00, bit 4) to OFF to cancel the latch request.
Signals Used for Latch
The phase-C pulse, or /EXT1, /EXT2 or /EXT3 signals can be used as a latch signal. Use the setting parameter Latch
Detection Signal Selection (OW
04, bits 0 to 3) to select the signal to be used as a latch signal.
Parameters Related to Modal Latch Function
The following table shows the parameters related to the Modal Latch function.
Parameter Type Parameter No. Parameter Name Description
Setting parameter
OW 00, bit 4 Latch Detection Demand
Executed when the bit 4 turns ON from
OFF.
Cancelled when the bit 4 turns OFF
from ON.
OW 04, bits 0 to 3
Latch Detection Signal
Selection
2: Phase-C pulse
3: /EXT1
4: /EXT2
5: /EXT3
Monitoring parameter
IW 0C, bit 2 Latch Completed −
IL 18
Machine Coordinate
System Latch Position
(LPOS)
1 = 1 reference unit
OW 00, bit 4
Latch Detection
Demand
t 2: 2 scans
t 1 : Communication cycle
Latch signal
t 3 : SERVOPACK preparation time for
 latch processing (҇4 ms㧕
IW 0C, bit 2
Latch Completed
∗ T ҈ t
1 + t 2 + t 3 ޓ where ޓT: Latch processing time
∗ T