Scanlab RTC 5 PC Interface Board - 6.2.3 Initializing the DLL and Board Management

RTC
®
5 PC Interface Board
Rev. 1.9 e
6 Developing User Applications
64
innovators for industry
6.2.3 Initializing the DLL and Board
Management
(1)
Any number of RTC
®
5 boards can be used simultane-
ously in one PC. Moreover, the RTC
®
5’s DLL allows
multi-threading as well as multi-processing;
therefore also any number of applications (user
programs) can be used simultaneously. However, no
board can be simultaneously used by multiple appli-
cations. Access rights (even if temporary) to existing
boards are assigned on an exclusive basis by the DLL.
Multiple threads of one application can use the same
board, but can not send commands to it at the same
time (the DLL automatically serializes the command
calls).
DLL-internal board management coordinates usage
of different boards by different applications. Board
management is initiated via the command
init_rtc5_dll (see page 306).This command is a
prerequisite for RTC
®
5 access and must be called at
the beginning of every application – even if only one
RTC
®
5 board is to be used by only one application.
The command:
• searches for all existing RTC
®
5 boards
• establishes corresponding board management
• automatically assigns the application access
rights to the found boards (as long as access
rights are not already assigned to another appli-
cation)
• assigns DLL-internal numbers for all found RTC
®
5
boards (important for multi-board commands)
• sets one board as the active board, which will be
the target for non-multi-board commands
For a detailed description, see page 306.
Further commands enable subsequent changes to
access rights and changing the active board. Usage of
multiple boards is described in chapter 6.6 "Using
Multiple RTC
®
5 Boards in One Computer", page 83;
usage by multiple applications is described in
chapter 6.7 "Usage by Multiple Applications",
page 85.
After DLL initialization via init_rtc5_dll, the user can
additionally select one of two operation modes (see
set_rtc4_mode, page 473 and set_rtc5_mode,
page 473). The default is RTC
®
5 mode. An RTC
®
4
compatibility mode is also provided so that applica-
tions written for the RTC
®
4 can be processed by the
RTC
®
5 (to a large extent) without modification.
However, a prerequisite here is that the program can
only contain RTC
®
4 commands that also exist with
unchanged functionality as RTC
®
5 commands. This
user manual’s list of commands (page 227), when
applicable, notes such changes in the
“RTC
®
4 RTC
®
5” section (also see section "Increased
Parameter Resolution" on page 33).
(1) The usage of all RTC
®
5 commands is identical under both the
32-bit and 64-bit versions of WINDOWS. Nevertheless, you
must always comply with the formats and value ranges of data
types used in RTC
®
5 commands (see page 226).