M2256PW 3M, M2256PW Datasheet - Page 38

• Manufacturer Part Number: M2256PW
• Description: LCD Touch Panels 22 M2256PW 20 Point Multi-Touch
• Manufacturer: 3M
• Series: -r
• Type: Capacitiver

Specifications of M2256PW

• Length: 18.6" (473.8mm)
• Width: 20.2" (513.2mm)
• Height: 11.6" (296.1mm)
• Interface: USB/Serial
• Diagonal Screen Size: 22" (559mm)
• Lead Free Status / Rohs Status: Details

38
Touch Data Format
where:
Tt
Ffff
Ss
The PX running with no errors returns the following string:
<SOH> AD****00 <CR>
The format includes two bitmapped ASCII hex status bytes. A “00” indicates no errors.
Table 19 Bit Meanings in Status Byte
The format is a six byte packet that includes one status byte, four bytes of binary X,Y
position data and a touch ID. The X,Y coordinates are 14 bits, providing a range of 0 to
16,383. The data is sent in the following format:
Bit
0
1
2
3
4
5
6
7
= Two ASCII characters that identify the controller type.
= Four ASCII characters that indicate the features supported by the
= Two ASCII characters that provide status information about the
AD
controller.
**** Indicates no additional features configured
controller hardware. The two characters represent one byte. Each
character is in the range 0 to 9 and A to F.
Table 2 defines the meaning of each bit in the status byte. Each bit
can be set to 1 or 0, where 1 = an error and 0 = no error. So a
response of:
00 = No diagnostic errors (normal response)
Description
Not used
ROM_ERROR
PWM Error
NOV_ERROR
HDW_ERROR
Not used
Not used
Not used
3M Touch Systems, Inc. Proprietary Information
Indicates the PX series of controllers
Notes
Code area checksum error
Touch screen not connected or potential problem.
Parameter Block1 checksum error
Problem with ADCs
3M™ Display M2256PW User Guide