Industrial Indexing Systems MSC-250 User Manual

IB-11B012 INDUSTRIAL INDEXING SYSTEMS, INC.
USER'S GUIDE MOTION CONTROL SYSTEM, MSC-250
1 - 8 DESCRIPTION MARCH 2003
When the absolute position of the system must be known, the system must be initialized
after it is powered up. For encoders with marker bits less than 180° of encoder shaft
rotation, use the find_mark_cw and find_mark_ccw commands to initialize the system
and determine the absolute system position. For encoders with marker bits of 180° of
encoder shaft rotation, use the find_tm_cw and find_tm_ccw commands. (Refer to the
Macroprogram Development System Instruction Book for complete command instructions.)
NOTE
The ability to find a marker or initialize the system is only valid when
the controller is being used as an active (versus passive) position
sensing device and does not affect the master angle data.
1.2.1.2 POS OUT Signal
The position of the encoder, as understood by the controller, is translated into a "POS
OUT" voltage signal based on a digital compensation gain algorithm. This algorithm has
four variable components of Proportional Gain, Integral Gain, Derivative Gain, and Feed
Forward Gain values which respectively represent the Proportional, Integral, Derivative,
and Feed Forward terms of the algorithm.
With standard values of Proportional Gain = 16, Integral Gain = 0, Derivative Gain = 0, and
Feed Forward Gain = 0, the POS OUT voltage signal is +5 VDC at the 90° encoder shaft
position and +10 VDC at the 180° encoder shaft position for clockwise shaft rotation. The
signal is -5 VDC at the 90° encoder shaft position and -10 VDC at the 180° encoder shaft
position for counterclockwise shaft rotation. However, the Proportional Gain value can be
set to produce a voltage signal of from 10 VDC per 1/32 revolution of the encoder shaft to
10 VDC per 8 turns of the encoder shaft. (Refer to the Macroprogram Development
System Instruction Book for information on setting the digital compensation values.)
1.2.1.3 Pseudo Axis
The pseudo axis is an imaginary, perfect motor which can be controlled by the software of
the MSC-250. The desired position of the pseudo-axis motor is determined by the
Macroprogram and the resulting position signal perfectly reflects the desired position at any
given time. This perfect-position information can then be used by the real axes as
reference information for their own movements or it can be used to actuate programmable
limit switches or other I/O functions. The pseudo axis information can be broadcast
(transmitted) on either or both of the controller master angle buses.

Industrial Indexing Systems MSC-250 Specifications

General

Brand	Industrial Indexing Systems
Model	MSC-250
Category	Controller
Language	English