PS288_OwnersMnl_PriorTo2009 - 第131页

System Theory • Vision System PS288 Owner’s Manual 4—7 motion controller interface card. When combined w ith the X–Y gantry sys- tem, devices may be picked up and pl aced into any physi cal location within the operating …

System Theory • Pick And Place System

4—6 PS288 Owner’s Manual

“Check doors/E-stop!” message appears on the screen. When the door is

closed and the message is cleared, motion resumes.

Safety shield condition is monitored by a human safety relay controller. The

safety shield interlock switches are connected in series and wired to the

human safety relay controller. Any open door breaks the circuit and provides

a signal representative of an open door to the human safety relay controller.

The human safety relay controller, in turn, relays the signal to the AH500

software and displays the “Check doors/E-stop!” message.

WARNING: Opening a safety shield stops the motion of the gan-

try and removes power from the gantry only. When the safety

shield is closed and the “Check doors/E-stop!” message cleared,

the gantry resumes its motion from the point where it stopped

moving.

Pick And Place

System

The PNP head consists of two motion subsystems: X- and Y-axes gantry sys-

tem, and Z- and R-axes motor system. A vacuum subsystem on the Socket

Actuator is used to pick devices from and place devices into their program-

ming sockets and input/output media. Together, these systems facilitate the

movement and proper placement of devices throughout the PS288.

Gantry System

The gantry system moves the PNP head on the X-axis and Y-axis. The sys-

tem is controlled by the AH500 software and moved with two servo motor

amplifiers. Each of the servo motor amplifiers is fed with 208–240 VAC via

the servo motor amplifier contactor controlled by the I/O Controller. Digital

encoders attached to the motors determine the PNP head’s position along the

lead screws and are accurate to within 0.0001 inches.

The servo motor amplifiers receive movement commands from the motion

controller interface card in the Handler Computer. Positional information

from the motor encoders is also interpreted on this card.

Home sensors for both axes provide reference locations for the gantry to

base movement distances upon, and are also monitored by the motion con-

troller interface card. Each of the optical sensors is powered by the 24 VDC

power supply described earlier in this chapter.

The motion controller interface card, in addition to the functions described

above, also provides commands and receives responses from the laser trans-

fer assembly (if installed) and the PNP head controls.

Pick And Place Head

The pick and place head facilitates movement on the Z-axis and R-axis

using an independent 24 VDC power supply to move the pick and place head

up and down, as well as apply rotational corrections. Its motion is controlled

by the motion controller interface card in the Handler Computer, and encod-

ers built into the pick and place head provide positional information to the

System Theory • Vision System

PS288 Owner’s Manual 4—7

motion controller interface card. When combined with the X–Y gantry sys-

tem, devices may be picked up and placed into any physical location within

the operating envelope.

The PNP head has an integrated probe tip through which a vacuum or posi-

tive pressure may be applied to attach or remove devices from the probe tip.

The probe tip is interchangeable to accommodate various sizes and package

types.

Socket Actuator

The Socket Actuator is a pneumatic driven solenoid used to actuate the sock-

ets before the PNP head places devices into or removes devices from them.

Sensors attached to the solenoid indicate the position of the Socket Actuator

and verify that it is safe to move devices to and from the socket.

The two sensors, one for the up position and one for the down position, are

adjustable for optimum sensing of the Socket Actuator’s position. When the

“up” sensor is active, the gantry system may retract the PNP head and move

to another area of the machine. When the “down” sensor is active, the PNP

head may extend to pick up a device from or place a device into a program-

ming socket. The Socket Actuator is not used when picking devices from or

placing devices into their input/output media.

Each sensor has an LED which turns red when the Socket Actuator is in the

up or down position.

Vision System

The vision system is used in conjunction with the PNP head to ensure accu-

rate alignment of the devices to be inserted into the sockets for program-

ming. Using data in a reference vision file for the device type to be

programmed, the PNP head can compensate for the misalignment of a device

in the X, Y, and R (up to 30 degrees) axes. Misalignments can be corrected

within 0.001 inches. The vision system cannot compensate for Z-axis errors.

The vision system consists of a camera, light ring, interface card, and soft-

ware. The light ring and camera are mounted onto a specialized bracket

below the work surface in a location dependent upon the configuration of the

machine. The interface card is installed in the Handler Computer, as is its

software interface.

The light ring is used to illuminate the device being analyzed by the camera

so that an accurate picture may be taken. The LED light source is powered

by 24VDC.

The camera is mounted to a bracket below the work surface and is optimally

focused onto a device attached to the PNP head when in the down position.

Focus and alignment data are set using the calibration routine described in

“Calibrating the Vision System” on page 5-41, and by the vision system soft-

ware.

System Theory • Input and Output Modules

4—8 PS288 Owner’s Manual

Input and

Output Modules

Devices may be presented to and re-packaged from the system in various

combinations. The input and output modules include:

• Tube input

• Tube output

• Tape input

• Tape output

• Tray input

• Tray output

These input and output modules may be used in any combination.

Tube Input and Output

The tube input and tube output modules are attached to the work surface

toward the front of the machine. Each module accommodates a number of

different sized tubes and each is adjustable. Tubes are inserted into the mod-

ules through holes in the safety shield designed for them. The input tube

module is slanted to cause the devices to slide toward the staging area, while

the output tube module is slanted to cause devices to slide away from the

staging area. There are no sensors to alert the user when a tube is full or

empty.

The tubes are gently vibrated to keep devices moving freely and reduce the

likelihood of device jams. The level of vibration may be varied using the

adjustment controls found on the right front panel of the machine. Each tube

vibrator is powered by 115 VAC from the I/O Controller.

Tape Input and Output

Manipulation of devices in a tape and reel form is supported in both input

and output modules, depending upon the configuration of the PS288. A tape

input feeder may be placed in a bracket on the right front of the PS288 to

provide the machine with devices to be programmed. Additionally, a tape

output system, attached to the Option Bay, can be equipped with either pres-

sure sealed cover tape or heat sealed cover tape capabilities.

The tape input feeder provides the system with devices to be programmed

via tape and reel. The tape is fed by a toothed sprocket along an adjustable

rail system. As the tape is fed, the cover tape is removed by a motorized

take-up reel, exposing the device to be picked from the tape. The tape is

advanced into the operating envelope one tape pocket at a time. Optical sen-

sors in the input tape module determine whether the tape pocket has a device

in place or is empty, as well as the position of the pocket in the tape. When

the PNP head removes the device from the tape pocket, the sensors detect the

pocket is empty and the tape is moved one position forward. Empty input

tape exits from the bottom of the tape feeder. It is not taken up on a reel, but

falls freely.

The tape output system allows programmed and marked (if a marking stage

is installed) devices to be placed in an output tape for use with another pick

and place machine on the production line or another facility. A reel of empty

pocket tape is placed on a spindle, and the tape is fed into an adjust-

able-width track. The tape is pulled through the track with a toothed sprocket

at a rate determined by the pitch (pocket size and distance) of the tape. Sen-