A-5
A1
A
ending in a CR, LF, or CR LF sequence. The data messages often
consist of eight-bit binary characters and end on a predetermined
count or when the talker asserts the EOI line simultaneously with the
last data byte. The controller-in-charge must be programmed to
correctly respond to each device's message termination sequence to
avoid hanging-up the system or leaving characters that will be output
when the device is addressed as a talker again.
IFC (interface clear) is sent by the system controller and places the
interface system in a known quiescent state with all devices
unaddressed.
REN (remote enable) is sent by the system controller and is used with
other interface messages or device addresses to select either local or
remote control of each device.
SRQ (service request) is sent by any device on the bus that wants
service, such as counter that has just completed a time-interval
measurement.
