FAQ: How is External Positioning (latch target) setup in an MP920/930 SVB mode over mechatrolink?
Breadcrumb
Contact Us
contactUsAction
External Positioning (EX_POSING) is essentially the same as what is commonly known as latch target. In this mode, the axis is commanded to make a move to an absolute distance. If it is interrupted by a latch signal, the axis will move a defined distance after the latch position.
Example using an MP920:
Assume the following:
- Control is via mechatrolink with SVB-01 module
- SGDH with NS100 module
- SGMAH motor with 13 bit encoder
- Using Axis #1
- Fixed parameter #8 = 2048 ppr (encoder resolution prequad)
- Fixed parameter #17 = 0013H (cmd unit in inches, elec gearing enabled)
- Fixed parameter #18 = 3 (three decimal places)
- Fixed parameter #19 = 5890 (5.890" per rev)
- Fixed parameter #21 = 3 (3:1 gear box)
- Fixed parameter #22 = 1
- Latch is wired into SGDH 1CN, +24VDC pin 47 (+24VIN), latch switch sink to common pin 44 (EXT1)
Note:
OLC012 = Absolute default move distance to move if latch is not received, in user units. Suppose the user would like to set the default move distance to move 1 rev of the final output shaft. This value would get set to 5890 (5.890" with 3 decimal places).
OLC024 = Latch distance to move after latch is received, in post quad pulses. Suppose the user would like to set the distance after latch to 1 rev of the output shaft. This value would get set to 24576 (2048ppr*4*3)
ILC008 = actual position feedback in user units
ILC006 = last latch position in user units
Sequence:
Check that system is ready and servo is enabled
Set OLC024 = 24576
Set OLC022 (speed)
Set OWC020=2 (Ext_Posing mode) AND OLC012=9000 at the same time (in the same scan)
If latch is not received, the position traveled should verify 9000 user units (ILC008)
If latch is received, the position traveled should verify 24576 pulses AFTER the latch position
meaning: ILC008-ILC006 should be equal to 5890 user units, and the output shaft should have turned 1 rev
(24576 pulse) * (1rev/2048*4pulse) *(1rev_out/3rev_in) * (5890usr_units/rev) = 5890 user units
A similar approach can be used when applying to an MP930
See attached .JPG below for a speed/distance chart.
SAFETY PRECAUTIONS AND INSTRUCTIONS FOR USE OF FAQ INFORMATION!
Please read and understand the product instruction manual before installing, servicing or operating Yaskawa products. FAQ content and illustrations are provided as technical advice to augment the information in manual, not supersede it. It is not possible to give detailed instructions for all types of installation or support activities. The information described in the FAQs are subject to change without notice to improve the product or FAQ. Yaskawa assumes no responsibility for errors or omissions or damages resulting from the use of the information contained in any FAQ. All warnings, cautions and product instruction for product use must be followed. Installation, operation and maintenance should be carried out by qualified personnel. Failure to observe these and other precautions highlighted in the product manuals will expose the user to high voltages resulting in, serious injury or death. Qualified personnel are defined as individuals who are familiar with the installation, starting, operation and maintenance of Yaskawa products of the type described and have proper qualifications to perform the work.
Phone
If you have an urgent request, please call: 1-800-YASKAWA (927-5292) or 1-847-887-7000.Electronically
To contact us electronically, please select your type of request and complete the form.Yaskawa America, Inc. - Drives & Motion Division
2121 Norman Drive South
Waukegan, IL 60085