Philips IntelliVue Series, Installation And Service Manual

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CareNet
2-36
Hardware Description
System
Communicatio
ns Controller
The
System Communications Controller (SCC)
is the active device of the SDN. Its
functions are to provide the communication link among instruments connected to the SDN,
establish SDN polling cycles, and control data flow, timing, synchronization, and distribution
throughout the system.The SCC is shown in Figure 2-36.
Figure 2-36 Serial Communications Controller
The SCC performs basic SDN fault detection to insure reliability of SDN system
communication as well as self-diagnostic routines for SCC fault detection, troubleshooting,
and servicing.
Warning For the Information Center system to comply with IEC 60601-1-1, a second Protective
Earth (PE) must be provided for the SDN. This is normally accomplished by providing a
second PE to the SCC. This is described in
Chapter 4 , Safety .
Note The Information Center can also monitor up to two telemetry mainframes without the need for
an SCC. In this application, the telemetry mainframe output is connected directly to the
Information Center’s SDN Interface Card input. Priority wire connections are required for this
application. See Figure 2-37.
SDN Interface
Card
The SDN Interface Card is the intelligent interface between the SDN and the PC host. It
receives and sends messages to and from other instruments over the SDN. A block diagram of
SDN Interface Card circuitry is shown in Figure 2-37.
Figure 2-37 SDN Interface Card Block Diagram
Branch Cables
SDN branch cables are installed to connect the SCC to wall boxes where SDN instruments are
connected. Branch cables can be of two general types -- shielded, Serial Distribution Cables
Branch
Cable PC
SDN Interface Card Circuitry
Transceiver
Circuitry
SIC µ P
PC Host
Chip Interface
PCI Bus
SDN
Serial
Bus