Service manual

Theory
3-15
MAIN SUBSYSTEMS and TASKS
• The SDLC subsystem sends packets from the modules to the rest of the system, including
Ethernet and GDS, and sends packets to modules.
• The Interpreter subsystem provides modules and keys with “primitives” that are used via table
code to create and control human interfacing on the monitor, such as touchscreen key presses. It
receives key presses from the user and notifies the Keyboard Interpreter that then runs the
appropriate table code program. That program uses the Key Display task to redraw the new key
state as feedback to the user.
• The GDS is the patient database containing parameter data from the modules, including current,
general, trend, and waveform data.
• The Remote Interface System handles Ethernet connections to remote monitors and modules. It
broadcasts the existence and configuration of the network devices to each other. It enables the
user to view remote parameters and to remotely press keys across the network. The Remote
Interface System downloads the module table code to remote monitors to create the same human
interface on multiple monitors. In addition, it supports the alarm watch and remote view functions
and handles multicasted waveform data.
• The Recorder subsystem controls local recorders and network recorders.
• The Alarm subsystem handles the standard Ultraview/UCN alarms. Modules send alarm
conditions over SLDC, and in response, the alarm subsystem sends alarm messages to the tone,
display, record, and network tasks. The module receives messages from the network for alarm
watch alarms and from SDLC tasks for module/channel adds or deletes.
MINOR SYSTEM TASKS and DEVICE DRIVERS
• The main Ultraview/UCN subsystems communicate display information to the Display Manager
(DM) task. The DM receives display changes from these subsystems and issues the appropriate
graphics primitives to update the display through the video device driver.
• The Ultraview/UCN subsystems interface to SDLC via Rx/Tx buffers in memory, driven by a
32-Hz interrupt.
• The Ethernet interface uses dynamic memory for receive and transmit. One Ethernet interrupt
occurs for both receive packets and command completes. An Ethernet write command is used for
transmitting packets. An “Ethernet-user” task maintains and uses a routing lookup table to switch
network packets to the appropriate network driver — the Ethernet device driver or the wireless
network card device driver.
The Ultraview/UCN recorder function uses these SDLC/Ethernet drivers directly.
The touchscreen driver and the external keyboard and mouse drivers provide x-y coordinates to the
keyboard task for activating the on-screen keys.
The tone task is responsible for timing and prioritizing tones from the Alarm subsystem, the Keys
subsystem, and other system tasks. It receives commands to turn ON and OFF, to suspend, and to
change volume. It also looks up wave table tones and sends them to the Mixer task. The Mixer task
mixes the alarm sounds with information tones as needed. These tasks talk to the audio hardware
via the audio device driver.