
Section 4 Serial Controller
4.58
READ
The
READ
command is used to accept data from the bus when in the Low Level
Controller Mode and return a machine readable bus status string.
READ
may only be used when the Analyzer488 is in the Listen State (see
LISTEN
) and handshaking is set to
STEP
(see
HANDSHAKE
).
READ
performs an
acceptor handshake. The
STEP
command is not required when using the
READ
command since the handshake is automatically performed when
READ
is executed.
This command does not have a query option.
TYPE Low Level Controller command
SYNTAX READ
RESPONSE Response is dependent on the data currently on the bus. Two
hexadecimal bytes are returned in the following format:
Hex Byte 1 Hex Byte 2
(bit positions) (bit positions)
(Control and Handshake Lines) (Data Lines)
8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1
REN IFC SRQ EOI DAV NRFD NDAC ATN D8 D1
MODE Low level controller
BUS STATES None
QUERY None
RESPONSE
EXAMPLES PRINT#1,"CONTROLLER OFF"
PRINT#1,"ASSERT IFC ATN REN"
PRINT#1,"UNASSERT IFC"
PRINT#1,"TALK"
PRINT#1,"HANDSHAKE STEP"
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