Citizen CL-E720DT Technical Manual page 73

[While receiving data]
Data0~7
Strobe
BUSY
Note: BUSY goes to "High" at the falling edge of Strobe, and data is latched at the leading
edge of Strobe.
[While receiving PRIME signal]
PRIME
BUSY
Ack
Fault
SELECT
Note: If the PRIME signal width is 10 µsec or less, it is not accepted.
BUSY goes to "High" when the PRIME signal is accepted by the printer.
0.5µs
0.5µs
10~15µsec or more
2-59
Chapter 2 Operating Principles
0.5µs
2-4. Interface
CL-E720DT