Fresenius Medical Care 4008 E Technical Manual page 427

Text display (circuit diagram 1/7)
The text display is an intelligent, 20-character display module. It is provided with its own
processor. Texts are loaded by means of ASCII characters via the data bus CS22. By means of
CS20 and via IC 73 and the data bus, the CPU can read whether the text display is ready to
receive new data.
UF displays (circuit diagram 2/7)
IC 3 and IC 4 are 8-digit seven-segment display drivers. IC 3 operates the UF Volume and UF
Rate displays. IC 4 operates the UF Goal and UF Time Left displays. These display drivers are
loaded in series with 16-bit packets upon each rising clock edge. This information is buffered into
the digit registers by means of the IC 5/16 and IC 5/18 load signals. Included in this information is
the brightness control.
Bar graph displays for arterial and venous pressure (circuit diagram 3/7)
IC 19, IC 16, and IC 22 are provided as data memories for the arterial bar graph display, whose
30 LEDs are organized within a 5x6 matrix. The 5 lines are directly energized via the emitter
sequence IC 30 by data buses DB0 to DB4 and the 6 columns via the 8-out-of-3 decoder IC 28 by
data buses DB5 to DB7. The actual value (CS1) is stored by IC 19; the upper limit (CS2) is stored
by IC 16; and the lower limit (CS3) is stored by IC 22. The respectively applicable LED is
energized via the clock inputs CL1, CL2, and CL3. The clock pulses of CL1 have a longer duration
than those of CL2 and CL3. Thus, the actual value is represented more brightly than the limits.
IC 18 (CS4), IC 15 (CS5), and IC 20 (CS6) are provided as data memories for the venous bar
graph display. The working method of this display is identical with that of the arterial bar graph
display.
Bar graph displays for TMP and conductivity (circuit diagram 4/7)
IC 59 (CS7), IC 55 (CS8), and IC 57 (CS9) are provided as data memories for the TMP bar graph
display.
IC 58 (CS10), IC 60 (CS11), and IC 56 (CS12) are provided as data memories for the CD bar
graph display.
The working method of both displays is identical with that of the arterial bar graph displays.
Bar graph displays for temperature and flow (circuit diagram 7/7)
The bar graph displays for temperature and flow are energized by of IC 24 via CS19. The data
lines DB4 to DB7 contain the value for the temperature display. Only 16 of the 20 LEDs of the
temperature display are actually visible. The data lines D0 to D3 contain the value for the flow
display. IC 72/19 is responsible for the brightness control of the temperature display, and IC 72/
18 serves to turn the display dark.
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Fresenius Medical Care 4008 4/09.03 (TM)