UART protocol between front panel board and digital board.
|Target version:||Keithley 2001 #6|
All display and key data transfer between CPU and front panel board is done by UART interface
Captured log example attached.
Display data transfered in ASCII + control bytes for blinking/special segments, etc.
R603,R604 on signal lines was probed with CP2103 USB-UART bridge
Settings: 8N1 9600 baudrate
Easy to use for custom application if perform full decode for protocol.
Requirement for front-panel board and VFD:
- +5.5VAC with center tap for filament
- +60 VDC for segment drive
- +5VDC for controller and logic
- 4MHz clock
- System reset signal line