Datex-Ohmeda S/5 Compact Anesthesia Monitor, Technical Reference Manual

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Datex-Ohmeda S/5 Compact Anesthesia and Critical Care Monitor
2 SYSTEM DESCRIPTION
2.1 Introduction
Datex-Ohmeda S/5 Compact Monitor builds up a freely configurable modular system. The
architecture is designed to enable different module combinations so that the user is able to get the
desirable parameter and feature set. This modular approach makes it possible to add new features
when they are needed.
2.2 Bus structure
The operation of Datex-Ohmeda S/5 Compact Monitor is based on two communication channels,
the CPU bus and module bus. All units, including the modules, receive power from the same power
supply unit, which is an integral part of the monitor frame.
486
Processor
PCMCIA Serial Ethernet Sound UPI
Chipset
Display
Controller
486 LOCAL BUS
ISA-BUS
DRAM
Reset
Logic
Non-
Volatile
Memory
Boot
Memory
Code
Memory
Patient
Module
Patient
Module
Patient
Modules
MODULE-BUS
cam_
p1_
gnr
l_
bus_s
tr
ct
r_
cm.
vs
d
The CPU bus is a communication channel
used only for internal data transfer. It is
based on the ISA bus used in IBM PC
computers. Data is transferred on this 16 bit
wide bus using the CPU clock frequency.
The module bus is for the parameter
modules. It bus is based on the widely used
industry standard RS-485, which uses a
differential serial method to transfer data.
This type of bus is robust and it allows
parameter modules to be inserted or
removed while the power is on. The module
bus uses a 500 kbps data transfer rate.
Figure 2 General bus structure of S/5 Compact Monitor
The RS-485 type of serial communication supports so-called multidrop or party line connections.
This means that all parameter modules connected to the module bus use exactly the same lines for
communication. The advantage of this is that all bus connectors are identical and the modules can
be connected in any order and position.
Document No. M1031508
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