Oki ML420 Maintenance Manual page 26

OPTXD
Power ON
OPCLK
OPRXD
Write instruction for IC
1
reset
OPCLR-N
IC write for LED data,
2
etc.
Reset
within IC
Read instruction for
3
data read
4
NO
Response check
for OK or NG
YES
Error notification
5
Instruction for
retransmission
6
1
7
8
2 3
bit0 bit7
Command (first)
bit0 bit7
Command response (second)
Command response (first)
Note
6
5 or 8
2
3 1
7
Command (second)