Communication Types - Motorola V186 - Cell Phone - GSM System Planner Manual

Communications
communication with the central. It also can act as a communication node (an
interconnection point between two or more different links) while performing its other
tasks.
The RTU network uses the MDLC protocol, which incorporates all seven layers of the
OSI model adapted for SCADA. It supports multiple logical channels per physical port,
enabling simultaneous central-to-RTU and RTU-to-RTU sessions. It also enables each
RTU to simultaneously run several kinds of communication applications, such as
reporting alarms by contention, on-line monitoring, performing diagnostics checks, etc.
The MDLC protocol is discussed later in this manual.
The ACE3600 System Tools Suite (STS) may perform monitoring, modification,
diagnostics, error logging, etc., on any RTU in the system from any RS232 port in the
system, configured as either RS232 Local Computer port, RTU-to-RTU RS232 (RS-
link1) or from any IP port in the system (not necessarily RTU port).

Communication Types

The RTUs in the system are linked to a radio or line network as defined by the system
engineer, according to user requirements. Each RTU executes its application and,
simultaneously, supports the communications link (or links) defined for it, and serves as a
network node, if so defined.
The ACE3600 system supports up to 29 line links (LINE 1 to LINE 29), up to nine radio
links (RADIO 1 to RADIO 9), up to 19 local RTU-to-RTU links (RS-link 1 to RS-link
19) that use RS232, up to 29 IP links (LINE 1 to LINE 29), and one dial link. Any of the
radios may be either conventional or analog trunked. Computers may be connected to the
ports configured as RS232 Local Computer, as local RTU-to-RTU link, or via Ethernet.
For conventional radios, up to nine zones can be defined on every frequency (of the nine
supported frequencies). A radio link for conventional radios is divided into zones when
not all sites can communicate with each other and F1/F2 repeaters (using two
frequencies) are not to be used. In this case, some RTUs will serve as Store & Forward
repeaters and the link is divided into zones.
A zone is defined as a group of one or more sites that can directly communicate with
each other without a Store & Forward repeater. The name of a zone is composed of the
link name and the zone number. For example, for RADIO 3 zone number 1 is named
RADIO 3/1, zone number 2 - RADIO 3/2 and so on.
After defining the communications network, the user must define the various links used
in the system as well as the RTUs that serve as nodes between the links. A network node
is an RTU that functions as an interconnection point between two or more different links.
A Store & Forward node, on the other hand, is a network node, which relays messages
using the same physical port.
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