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CARROLL TOUCH Chapter 5 - Smart-Frame Protocol II
Touch System Programmer’s Guide 5-5
Types of SFP-II Functions
SFP-II functions are currently grouped into four logical categories. The
logical categories are reserved in groups of 16 (10H), with each group
containing functions that have similar purposes.
• Reset and touch reporting:
GetTouchState (01H)
• Status reporting:
GetCoordinateRanges (10H)
GetConfiguration (11H)
• Parameter setting and reporting:
SetTouchModes (20H)
SetReportProperties (21H)
SetReportTransferMode (22H)
• Mode switching:
SwitchToClassicSFP (64H)
GetProtocolVersion (65H)
Functions
Touch systems that support SFP-II communicate with applications and
drivers via the use of SFP-II functions. Each function consists of a
command and a corresponding report, even if that report is simply a
null report that only returns the report number and the command error
status. The report number is the same as the command number for each
command/report pair.
Each command/report pair may be thought of as corresponding to a
function call in a language such as C, with the command parameters (if
any) representing the parameters that are passed into the function, and
the report parameters (if any) representing the parameters that are
returned by the function.
The host computer sends SFP-II commands to the touch system, and the
touch system responds by sending SFP-II reports to the host. The touch
system must respond with the corresponding SFP-II report packet for
each and every SFP-II command packet that it receives. The host, in
turn, must wait until it receives the corresponding SFP-II report packet
after sending an SFP-II command packet before it can send another
SFP-II command packet.
The host should use a one second timeout when waiting for the report
packet. If the report packet has not arrived after that time, the host
should retry sending the command. If the touch system still does not