3M M2256PW Manual De Usuario

3M™ Multi-touch Display M2256PW User Guide 

 

25 

3M Touch Systems, Inc. Proprietary Information – 37531 Rev D

POC Status – The status of the Power-on Checks.  Various controller systems are 
checked at power-up. If any failures in these systems are detected, a POC flag is set. The 
POC status field reports the state of these flags. 

0 Not 

used 

 

1 

ROM_ERROR 

Code area checksum error 

2 

PWM Error      

Touch screen not connected or potential problem 

3 

NOV_ERROR 

Parameter blocks checksum error 

4 

HDW_ERROR 

Problem with ADCs 

5--7 Not 

used 

 

Cmd Status – The status for the last command request. This field is used to determine 
whether the last request was processed successfully. It is also used to track the progress 
of a multi-stage request, such as 2 point calibration. The Status Request does not affect 
the contents of this field, i.e., successful or unsuccessful processing of a previous status 
request does not cause the command status field to be updated. 

0 

Failure in command processing 

1 

Command being processed 

2 

Stage 1 processing complete (for multi-stage commands) 

3 Command 

complete 

4  

Soft Reset Occurred 

5 

Hard Reset Occurred 

6 -- 7 

Not used 

This is a request to send information that indicates the maximum number of 
simultaneous touches supported by the controller. 

0 bmRequestType 

1 

0xA1 

Class,D2H,Interface 

1 bRequest  1 

0x01 

Get 

Report 

2 wValue 

2 

0x0312 

msb=03=Feature 

 

lsb=12 Feature Report ID 

4 wIndex 

2 

0 Always 

0 

6 wLength 

2 

2 Always 

2