Specifications

Chapter 1 MicroTouch Touchscreen Controllers 21
Receiving Responses from the Controller
After executing a command, the controller returns a response or
acknowledgment to the host system. Each controller response consists
of a header, the command response, and a terminator in the following
format:
<Header>Command Response<Terminator>
Note:
The following descriptions of header, response, and terminator,
use MicroTouch’s terminal emulator key sequences. The format of
controller responses varies depending on the terminal emulation mode
you are using.
The header is the first character in the response string and is the
ASCII start-of-header character <SOH>. An ASCII <SOH> character
is equivalent to 01 hexadecimal. The value returned will be the ASCII
key sequence Ctrl A (^A).
The response, which always follows the header, is usually a range of
ASCII characters depending on the type of command received.
Responses can be in many forms.
For example, one standard response is <SOH>0<CR> (ASCII
character ‘zero’ or 30 hexadecimal). This response indicates a
successful command completion. The controller received a valid
command and executed the command properly.
Another standard response is <SOH>1<CR> (ASCII character ‘one’
or 31 hexadecimal). This response indicates the command failed. The
controller received an invalid command and did not execute the
command. Here are some possible reasons for the failure:
The command was not formatted correctly.
The system parameters were not set up to allow command
execution.
The controller does not support the command.