Theory of Operation
42
40-5648-51B
Front panel interface description
The
keypad interface has two circuits:
•
the interface to the LED’s
•
the interface to the keypad switch matrix, and power
switch.
LED(s) Drive
Circuits
LCD Input Data
Control Circuits
Front Panel
(Keypad)
Enable
Row Scan
Column Select
I/O Exp #2,
PC0-PC7
I/O Exp #1,
PA0-PA5
I/O Exp #2,
PC0-PC3
Flow Chart of Front Panel Function
LED drive circuit, Q26, Q27, Q40, Q33 - Q37
Each LED drive circuit has a logic controlled switch
providing a pseudo-current source to the LED when
activated.
•
All LED’s except the “Warning”, “Battery Charge”,
and “AC Power” LEDs, are controlled exclusively by
the main microprocessor.
Keypad matrix interface
A 4 row by 6 column scan matrix senses the front panel
keys:
•
A pressed button is read from column signals, key
-
pad_in_colx, through the 82C55 port expander #1.
A button press is sensed as a logic low.
•
The keypad row signals are output from port C of
the 82C55 port expander #2.
Power switch interface
The power switch has a circuit separate from the keypad
matrix because it is monitored by both the main micro-
processor and the auxiliary controller.
Содержание Medfusion 3000 Series
Страница 1: ...s Medfusion 3000 Series Technical Service Manual ...
Страница 2: ...Table of Contents ii 40 5648 51B ...
Страница 20: ...Introduction 14 40 5648 51B ...
Страница 32: ...Scheduled Maintenance 26 40 5648 51B ...
Страница 80: ...Troubleshooting 74 40 5648 51B ...
Страница 116: ...Calibration Adjustment 110 40 5648 51B ...
Страница 158: ...Assembly Drawings Parts Lists 152 40 5648 51B Medfusion 3000 series main pump assembly See Note 1 ...
Страница 160: ...Assembly Drawings Parts Lists 154 40 5648 51B Case bottom assembly Medfusion 3500BC ...
Страница 162: ...Assembly Drawings Parts Lists 156 40 5648 51B Case top assembly w plunger ...
Страница 164: ...Assembly Drawings Parts Lists 158 40 5648 51B Case top assembly without plunger ...
Страница 167: ...Assembly Drawings Parts Lists 161 40 5648 51B Barrel clamp assembly GREASE SILICONE III SOLDER NO CLEAN ...
Страница 172: ...Assembly Drawings Parts Lists 166 40 5648 51B Accessories parts list Poleclamp assembly ...
Страница 182: ...Index 176 40 5648 51B ...
Страница 183: ......