Keithley 2000, User Manual, Page: 257 / 280

Through the use of control lines, a handshake sequence takes place in the transfer process of
information from a talker to a listener. This handshake sequence helps ensure the credibility of
the information transfer. The basic handshake sequence between an active controller (talker) and
a listener is as follows:
1. The listener indicates that it is ready to listen.
2. The talker places the byte of data on the bus and indicates that the data is available to the
listener.
3. The listener, aware that the data is available, accepts the data and then indicates that the
data has been accepted.
4. The talker, aware that the data has been accepted, stops sending data and indicates that
data is not being sent.
5. The listener, aware that there is no data on the bus, indicates that it is ready for the next
byte of data.
IEEE-488 Bus Overview E-3