D-14
IEEE-488 Bus Overview
Model 6487 Reference Manual
Interface function codes
The interface function codes, which are part of the IEEE-488 standards, define an instru-
ment’s ability to support various interface functions and should not be confused with pro-
gramming commands found elsewhere in this manual. The interface function codes for the
Model 6487 are listed in
.
The codes define Model 6487 capabilities as follows:
SH (Source Handshake Function)
—
SH1 defines the ability of the instrument to initiate
the transfer of message/data over the data bus.
AH (Acceptor Handshake Function)
—
AH1 defines the ability of the instrument to
guarantee proper reception of message/data transmitted over the data bus.
T (Talker Function)
—
The ability of the instrument to send data over the bus to other
devices is provided by the T function. Instrument talker capabilities (T5) exist only after
the instrument has been addressed to talk.
L (Listener Function)
— The ability for the instrument to receive device-dependent data
over the bus from other devices is provided by the L function. Listener capabilities (L4) of
the instrument exist only after it has been addressed to listen.
SR (Service Request Function)
— SR1 defines the ability of the instrument to request
service from the controller.
RL (Remote-Local Function)
— RL1 defines the ability of the instrument to be placed in
the remote or local modes.
Table D-7
Model 6487 interface function codes
Code
Interface function
SH1
AH1
T5
L4
SR1
RL1
PP0
DC1
DT1
C0
E1
TE0
LE0
Source Handshake capability
Acceptor Handshake capability
Talker (basic talker, talk-only, serial poll, unaddressed to talk on LAG)
Listener (basic listener, unaddressed to listen on TAG)
Service Request capability
Remote/Local capability
No Parallel Poll capability
Device Clear capability
Device Trigger capability
No Controller capability
Open collector bus drivers
No Extended Talker capability
No Extended Listener capability
