IOtech Digital488 - Control Lines; Clear

Section 2 Getting Started
2.6
45
SERVICE INPUT
(Input).
46
EXTERNAL DATA READY [EDR]
(Input).
47,48 Not used.
49
+5 Volts
(
Do not exceed 50 mA load
).
50
I/O COMMON (Gnd).
2.3.3 Control Lines
Five control lines enable handshaking of digital I/O data transfer to the
Digital488
. They are automatically activated with the corresponding I/O
activity and can also be independently activated with the
Handshake
(Hn)
command.
2.3.3.1 Clear
(Pin 41)
The
Clear
output is pulse for approximately 50
microseconds after a Device Clear (DCL), Selected Device Clear
(SDC), or Interface Clear (IFC) command has been sent on the bus.
The
Clear
line is normally active high. The
Invert
command (
I8
)
will program it active low. The
Handshake
command
(H0)
can
pulse the
Clear
line, independent of any I/O operations.
Timing Diagram for Clear Output
Clear
65 µS typ 50 µS typ
DCL, SDC or IFC