User's Manual

Boomer II User Manual & Integrator’s Guide ______________________Appendix B – SDK NCL-API and Port Server
BM210012WT37 97 Copyright Wavenet Technology © November 2003
LAYER NAME CONTENT FUNCTION
1. PHYSICAL / BIT TRANSFER
LAYER
Extender Port to RPM. 9600, 8, 1, N on serial port and a wakeup line.
Wavenet’s current NCL API protocol stack is implemented with the
hierarchical structure. All DLLs including MSMQ files are included in
the install cabinet files for the VDD.
Message Router
The PC or PPC loads MSMQ as a device driver. Applications using the
modem must open a session with VDD by calling ‘VDDOpen()’ which
will create a private Receive MSMQ queue for the instance of the
application (client). The name of this private queue will be sent to the
serial port server (VDD) along with an open session request. The port
server will in turn create a private MSMQ queue to receive data from
the client. All Modem Events and response messages to be
communicated between the VDD and the application will be via the
receive queues. Transmit function requests from the applications
(clients) are queued by the VDD and are processed as a FIFO buffer by
the NCL interpreter. On Wakeup the VDD will be activated, if any
applications receive queues are open the RX event will be posted to
those queues. If no receive queues are active, the VDD will buffer the
RX events and start up the registered on_wakeup applications. After
the applications have successfully opened a VDD session the VDD will
pass the RX events to those applications.
NCL Interpreter
The NCL Interpreter strips NCL API function calls from application
messages, queue the calls and execute the calls on a FIFO basis.
Received messages will be queued and matched against an appropriate
request (if not an event), and passed to the router with the
corresponding tags.
Link Layer
The RPM communicates with a PC via a standard communications port
and a user supplied RS232 to CMOS level device. For the Pocket PC
(PPC) the RPM communicates via the PPC extender port UART. The
PPC performs an auto detect and wakeup when an attached modem
receives some data and the PPC is in suspend mode.
Application Interface
 Opening a Session
Applications are required to first open a session with the VDD by
calling the API function ‘VDDOpen()’. Singlesession applications can
also call ‘VDDOpenPort()’. All other API functions will return an
error until an open session with the VDD is established using one of
these calls.