Manual Modem PCDxx7 Serie│Doc. 26/793; Ed. E2│30.04.2005
Structure
Introduction
1-1
1
Saia-Burgess
Controls Ltd.
1
Introduction
The modem library for the PCD xx7 serie allows a quick integration of telecommuni-
cation through phone line inside your S7-project. It has been made flexible to be able
of supporting most of the analog modem found on the market.
At the moment the library supports the following communication types:
●
Between PCDs with the protocol (ASCII,RK512,DK3964 ) as Master or Slave.
●
Between PCD and Supervisor with the protocol (ASCII,RK512,DK3964 ) as
Master or Slave.
●
Between PCD and PG with the MPI protocol as Master or Slave.
●
Between PCD and SMS Center with the protocol UCP (send SMS)
The flexibility of the library function gives the possibility to add new communication
types without investing too much in development.
1.1
Structure
The modem driver is based on one main function block (FB-Modem DRIVER) which
handles the command “sent to the modem” and “the answer received from the mo-
dem”. It controls the modem status and allows the other telecommunication function
to proceed. This function has to be called cyclically.
The modem DRIVER is referring to a Data Block (DB_Modem), which contains all the
internal parameters of the driver, status and also all the configurable parameters to
adapt the driver to your application and modem.
The calling function give the possibility to the system to call and connect with other
subscriber. This function doesn’t have direct access to the modem, in fact all the
request are transmitted to the DRIVER through the DB_Modem and the DRIVER is
then executing them.
When the connection with the other subscriber is established, then the serial COM
can be use directly by other function or process. The modem DRIVER stay in back
ground task to survey they status of the connection.
The actual function which are also implemented in the library are:
●
Switching protocol to communicate with subscriber
●
Sending SMS
●
Sending Pager messages
