ProSoft Technology MVI46-103M - Manual (Page 27)

Functional Overview MVI46-103M ♦ SLC Platform
IEC 60870-5-103 Master Communication Module
ProSoft Technology, Inc. Page 27 of 187
September 12, 2006
3.2 Master Driver
The master driver supported on each application port of the module emulates an
IEC 60870-5-103 Master device. Configuration of each port is independent and
should be connected to different serial networks.
Each port on the module communicates with one or more controlled stations on
what are referred to as sessions. A session represents a controlled device with a
unique data link layer address. Each session (controlled device) contains one or
more data sets (sectors) that are defined by the vendor of the device. The
following illustration shows these relationships.
Port 0 on the module communicates with 4 sessions (0, 1, 3 and 4) each of which
has their own data set(s). Session 1 only has one sector (all data for device
contained in a single database). This sector is addressed by the master using the
Common address of ASDU value set for the sector in the configuration file.
Session 0 contains two sectors each with their own unique Common address of
ASDU value to identify the sector.
Port 1 is connected to one device on the network. This device is defined in the
Session 2 section of the configuration file. In this example, all data of the device
is stored in a single sector.
Note:
The IEC 60870-5-103 specification only supports the unbalanced mode.
No support is given in the protocol for the balanced mode and the module
does not support this mode.
The module supports two application ports. Thirty-two sessions can be defined
on the module with each session being assigned to an application port. Within
each session, up to five sectors can be defined. This system permits a very
flexible assignment of resources in the module. The definition of the data