Toshiba E-STUDIO520 - Setting the SMB Protocol

e-STUDIO520/600/720/850 CONTROL PANEL March 2005 © TOSHIBA TEC
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4) Data transmission
Fig.5-8
5.4.2 LED display circuit
Method of LED display
Example: Displaying "COPY"
Fig.5-9
The transistors (Q19 and Q1) are turned ON when the COM1 signal becomes Low level.
Also, when OUTP5 signal changes to Low level, the current flows from +5.1VA via the transistor (Q1) to
the LED10-1 (COPY) to turned ON the LED10-1.
Conditions to turn ON the LED
1) The transistor (Q1) connected to the LED anode is ON.
2) The transistor (Q7) connected to the LED cathode side is ON.
The LED is turned ON when 1) and 2) are satisfied.
LOAD
FRAME
LOAD
240 1 2 240
CP x (640/4) pulses
1 2
240
1/tF1/tF
1 2
FRAME
D0-D3
CP
Low
Low
(COPY)
LED10-1
G
Q7
Q1
+5.1VA
SG
SG
Q19
COM1
OUTP5
Current