Keithley IE-488 Manual page 10

GPIB IEEE488 MANUAL
7. Clear Lockout (Local Message) ---
8. Service Request
Message - - - - - - - - -
9. Status Byte
Message -------------
10. The Status Bit Message ---------
11. The Pass Control
Message -------
12. The Abort Message --------------
GENERAL
Clears all devices on the
GPIB and sets in local mode.
Any device
may
send this at
any
time
to request service
from the controller. This
is
cleared
by sending the
device's Status Byte Msg.
if the device no longer
requires service.
A data byte that represents
the
status of
one device
on the bus.
Bit 6 is set if
the device sent a Service
Request Message, and the
remaining bits are unique,
to the selected device.
A byte which represents the
operational conditions of a
group
of devices on the
bus. Each bit represents a
device on the bus. This is
typical response to a Para-
llel Poll operation.
This allows transfer of the
bus
management
duties to
another device on the bus.
The
System
controller takes
unconditional
control of
the bus from the active
controller.
The
message
terminates communications
with
the bus
and sends a
Clear All
message.
********* IEEE488 GPIB FUNCTION CLASSIFICATION TABLE ************
T6
-- Basic Talker, Serial Poll, Unaddressed if MLA
TEO -- No extended talker function
II4 -- Basic Listener, Unaddressed if MTA
LEO
-- No extended listener function
SHl
-- Complete Source Handshake capability
AH1
-- Complete Acceptor Handshake capability
SRl
-- Complete Service Request capability
PPl
-- Parallel Poll Remote configuration capability
RLl -- Complete Remote / Local capability
DC1
-- Complete
Device
Clear capability
DTl
-- Complete Device Trigger capability
Cl,C2,C3,C4,CS - CONTROLLER states
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