Vista Rail System Module.pdf - 第9页
5$,/6< 67(002' 8/( '5,9( 6$ 1'6( 1625 6 Chapter Issue 1 Sep 02 Technical Reference Manual 12.9 Board at Lef t /Right Sensors The board a t lef t and boar d at ri ght sensors are dif fuse opto type s…
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12.8 Technical Reference Manual Chapter Issue 1 Sep 02
Rail Home Sensor The rail home sensor is a through beam opto type sensor.
The sensor is used for accurately determining the front and rear rail widths.
During machine initialization, (power-up or upon exiting diagnostics), the rear
rail moves to the rear of the machine where upon the rail opto vane enters the
rail home sensor, the rear rail is now at the home position.
NOTE
Homing Sequence of this chapter refers.
The rail home sensor feeds directly to the Multiplexer controller and is used to
set the datum value for the rail width (609.5mm - 610.5mm).
Figure 12-5 Rail Home Setting
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Chapter Issue 1 Sep 02 Technical Reference Manual 12.9
Board at Left/Right
Sensors
The board at left and board at right sensors are diffuse opto type sensors.
These two sensors are used to detect a board at the input and output of the
transport belt. As the machine is bi-directional the functions of both optos are
reversed when the pass through direction is changed.
The input sensor is used to start the transport belt on detection of a board. The
board is transported into the machine and processed after which it is transferred
to the output sensor where it stops and waits for the command to be passed
onto the next machine in the line.
These optos are fitted with a red and green LED along with a sensitivity control.
There is a small amount of positional adjustment in the bracket but generally it
is not necessary to reset it as the footprint used by the diffuse opto is large
enough to cope with the holes in an average production board.
Figure 12-6 Board at Left/Right Opto Locations
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12.10 Technical Reference Manual Chapter Issue 1 Sep 02
SEQUENCES
Homing Sequence The rail system is homed during machine initialization only, (during power-up or
upon exiting diagnostics).
When the home command is received the rear moving rail is driven (in the
reverse direction) to the rear of the machine until the home vane, attached to it,
is detected by the rail home sensor. Upon detection (sensor ON) the motor is
driven in the opposite direction until the vane clears the home sensor and the
motor stops (sensor OFF).
This position has a set dimension of 609.5mm to 610.5mm measured between
the inside of each rail, (Positioning section of this chapter refers)
Figure 12-7 Rail Timing Diagram
Rail Positioning There is a fixed relationship between steps of the stepper drive motor and rail
movement (in mm) due to the gearing ratios and pitch of the driving leadscrews.
Therefore when a width is selected this is multiplied by the steps/mm factor and
sent to the stepper drive system.
All positions are relative to the home position.
Home Position
Fwd
Stepper
Motor
Home
Sensor
0V
12V
Stopped
Rev
Vane leaves sensor
Vane enters sensor