Wavenet Technology Pty Ltd. BM2900D Benutzerhandbuch

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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.