Document Number: 37026

Revision 05-Dec-00

www.vishay.com

6

TIP-3526PCS-8

Vishay Dale

COMMAND/RESPONSE DESCRIPTION (Continued)

Enable automatic reporting (29)

*Disable automatic reporting (scan but no report) (2A)

Request one coordinate report (2B)

When AUTOMATIC REPORTING is enabled, coordinate

reports are reported to the host as soon as they become

available. After issuing the ENABLE AUTOMATIC

REPORTING command, there may be a report in the

internal buffer which is not current. If a sufficient amount of

time has passed to allow this condition, the first coordinate

report returned should be ignored.

When AUTOMATIC REPORTING is disabled, no coordinate

reports are reported unless requested with REQUEST ONE

COORDINATE REPORT. If a stylus is entered into the

touch panel after AUTOMATIC REPORTING is disabled, a

coordinate report will be generated and saved in an internal

buffer (depending upon coordinate reporting modes in

effect) but will not be transmitted until a REQUEST ONE

COORDINATE REPORT command is received.

If no coordinate report is available in the internal buffer, the

touch panel will return a code 48 and continue to scan until a

stylus is detected. However, no coordinate report will be

reported until AUTOMATIC REPORTING is enabled or the

report is requested with REQUEST ONE COORDINATE

REPORT.

Coordinate reports are reported with the following format:

Report Type = 41, 42, 43 or 4E

xx yy = binary X and Y, > = 0, X, Y = FE if non-contiguous

Enable beeper (2D)

*Disable beeper (2E)

Enabling the beeper sends a logic 0 (active state) to pin 2 of

J4 depending on which of the coordinate reporting modes

are enabled. If the ENTER mode is enabled, a pulse is sent

for every entry point. If the EXIT mode is enabled, a pulse is

sent for every exit point. If both modes are enabled, a pulse

is sent for every entry and exit point. CONTINUOUS and

TRACKING modes have no beeper outputs.

Sound beeper, tt = duration (00 to FF) (2Ftt)

This command sends a logic 0 (active state) to pin 2 of J4.

The duration of the beep can be controlled in 10 msec

increments from 0 msec (00) to 2.55 sec (FF). Note: 2C

may not be used as an argument as it will cause a reset.

*Normal X (36)

Invert X (37)

*Normal Y (38)

Invert Y (39)

The standard configuration for the touch panel places the

XY origin at the lower left corner, consistent with the

Cartesian coordinate system. Upon issuing the INVERT Y

command, the origin becomes the upper left corner,

consistent with the video industry standard. These

commands allow the user to move the origin to any corner to

accommodate different standards or third party mechanical

packages which may have the touch panel rotated 180

degrees on the display. To cancel an INVERT X or INVERT

Y command, a NORMAL X or NORMAL Y command must

be executed.

These commands may also be implemented with jumpers.

Placing a shunt on Jumper B (NOR X) causes X data to be

normal (default) and removing the shunt causes inverted X

Request failed beam report (28)

This command returns the address of any infrared diode/

phototransistor pair that are blocked (as when a stylus is in

the panel) or have several failed scans. (The time period

can be extended by using the FAILED BEAM TIME-OUT

command.)

The report uses the following format:

47 = start of failed beam report

aa - nn = physical address of failed LED/

Phototransistor pair

FF = end of report

Reset touch panel (2C)

After issuing the RESET command, the touch panel is

returned to its power up condition and all operating modes

are returned to their default state and the buffer cleared. If

autobaud is being used the correct baud rate must again be

established.

Request software revision number (30)

Request touch matrix size (33)

Request model number (35)

These commands are provided for configuration control and

diagnostic purposes.

RS-232 framing or overrun error (45)

An RS-232 error indicates communication problems.

Buffer over flow error (4F)

Buffer overflow occurs when the input command buffer is

exceeded to lack of handshaking.

data. Similarly, placing a shunt on Jumper C (NOR Y)

causes Y data to be normal (default) or removal causes

inverted Y data. The jumper selected options may be

overridden with the software commands.

Failed beam time-out (3A t)

If any IR beam is broken for an extended time due to

blockage of the beam or failed optical components, the

touch panel will ignore that beam after a predetermined

number of scans. (This is to prevent failed beams from

interfering with touch sensing.) The actual failed beam

detection time depends on the modes of operation and the

size of the touch matrix. When using the CONTINUOUS

mode with AUTOMATIC REPORTING enabled, the time is

typically 25 - 30 seconds. If the application requires longer

touch times, then the time may be extended using the

FAILED BEAM TIME-OUT command. The command

accepts arguments from 1 to F.

INITIALIZATION

Initialization is performed by the host computer and must be

done each time the touch panel is powered up or the RESET

TOUCH PANEL command is issued. The process begins

with baud rate selection (if not jumper selected). The

remainder of the initialization process requires setting the

desired coordinate reporting modes, enabling or disabling

AUTOMATIC REPORTING, enabling or disabling the beeper,

and enabling or disabiling the touch panel. Default settings

are shown in the COMMANDS table.

When touch coordinate information is required by the host

computer, the touch panel must be enabled. The flow of

touch coordinates from the touch panel to the host computer

can be controlled by enabling or disabling AUTOMATIC

REPORTING. With AUTOMATIC REPORTING enabled,

coordinate reports are sent to the host as soon as they

become available. If the host computer is performing a task

which does not require touch coordinate information,

AUTOMATIC REPORTING may be disabled.