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Infrared protocol suites as standard, together with the PLP Link Protocol, which is used for PC
integration.
8.4.8.5 Comms database server
The comms database is implemented using EPOC’s DBMS server and is the central repository of
all information regarding phones, modems, protocols, network access phone numbers, Internet
addresses and physical locations, together with details of device drivers available to the system
servers and the EPOC kernel. The control panel is generally used to create and update entries in
this database, though it can also be written to by other software components such as installation
programs. The database also records default settings current at any time.
This makes it possible to write components which are both easy to use and genuinely device
independent. For example, a program that needs access to a serial service can consult the comms
database to identify the default module to load, with a simple optional dialog box being used to
allow the user to confirm the setting. No lines of code need be changed to allow such a program
to function with standard RS232 serial lines, or IrCOMM infrared protocols, or any other current
or future type of serial port.
8.4.8.6 Fax
The telephony server contains a separate fax server, which implements the fax transport protocols,
provides raw send and receive support, and offers its clients a dedicated fax session API. On the
client side, a fax data store is provided, together with views for stored faxes which provide fast
navigation and zooming. A fax printer driver allows any application that can print to send faxes.
Faxes are integrated with the EPOC Email application. Outgoing faxes are stored in the outbox
and sent when convenient; while incoming faxes are placed in the inbox.
8.4.8.7 Infrared
Infrared support assumes the availability of a serial infrared (SIR) device on EPOC hardware. A
full IrDA stack is supported by EPOC. The sockets server provides IrLAP, IrLMP, IrTinyTP,
IrObex and IrMUX; IrCOMM is provided as a serial service, which uses the underlying IrDA
sockets services.
EPOC fully supports “beaming” data over the infrared connection. All kinds of data can be sent
from one EPOC machine to another. Additionally, information from applications such as Agenda
and Contacts can be transferred to and from non-EPOC systems provided they support the IrObex
mechanisms for infrared object exchange and are capable of understanding the industry standard
vCalendar and vCard data formats.
Infrared printing is also supported.
8.4.8.8 PC integration
The EPOC side of PC integration consists of the PLP Link Protocol. Using PLP in EPOC builds
on an established and proven protocol, with a wide base of existing users of Psion machines. It was
specifically designed for mobile ROM based computing, and combines a very small memory
footprint with ease of use and reliability. The data link and transport portions of PLP run over a
point-to-point serial connection, and are loaded by the sockets server as the
plp.prt
protocol
module. Both RS232 and IrDA links are supported.
PLP accesses the protocol module via a session server,
plpsvr.dll
. As well as being a client of
the socket server, this component is a server in its own right, providing facilities for both local
and remote clients. As well as controlling the remote link on the EPOC device, it offers clients
access to a remote filing system. Importantly, it also specifies an interface for loadable .
rsy
remote server modules which can be invoked by its clients during a communications session; it is
therefore possible to extend the system by adding custom modules. Those provided include a
remote procedure call server and Windows printing. These facilities are directly used by EPOC
Connect and MacConnect to provide backup to desktop machines, an interface for application
installation, and the means for file format conversion and synchronisation.
