The interface function codes, which are
part
of the
IEEE-488-1978 standards, define
an
instrument's ability
to
support
various interface functions
and
should
not
be
confused
with
programming commands found else-
where
in
this manual. The interface function codes for the
Model236 /237/238 are listed
in
Table
B-1.
The codes
de-
fine Model236/237 /238 capabilities as follows:
SH
(Source
Handshake
Function) -
SHl
defines the
ability of the instrument to initiate the transfer of
mes-
sage/
data over the data bus.
AH
(Acceptor
Handshake
Function)-
AHl
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
(T6)
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 capabili-
ties
(L4)
of the instrument exist only after
it
has been ad-
dressed to listen.
SR
(Service Request
Function)-
SRl
defines the ability
of the instrument to request service from the controller.
RL
(Remote-Local
Function)-
RLl defines the ability of
the instrument to
be
placed in the remote
or
local modes.
PP (Parallel Poll Function) -
The
instrument does
not
+
+
APPENDIX 8
Interface Function Codes
have parallel polling capabilities
(PPO).
DC
(Device Clear
Function)-
DCl
defines the ability of
the
instrument to
be
cleared (initialized).
DT
(Device Trigger Function) - The ability for the
in-
strument to have its readings triggered is provided DTl.
C (Controller
Function)-
The instrument does not have
controller capabilities
(CO).
TE
(Extended
Talker
Function) - The instrument does
not
have extended talker capabilities
(TEO).
LE
(Extended Listener
Function)-
The instrument does
not have extended listener capabilities
(LEO).
E (Bus
Driver
Type)
-The
instrument has open-collec-
tor
bus
drivers (El).
Table
B-1. Model236/237/238 Interface
Function
Codes
Code Interface Function
SHl
Source
Handshake capability
AHl
Acceptor Handshake capability.
T6
Talker (basic talker, serial poll, unaddressed
to talk
on
LAG)
L4
Listener (basic listener, unaddressed to listen
on
TAG)
SRl
Service Request capability
RLl Remote/Local capability
PPO
No
Parallel Poll capability
DCl
Device Clear capability
DTl
Device Trigger capability
co
No
Controller capability
El
Open
Collector Bus Drivers
TEO
No
Extended Talker capabilities
LEO
No
Extended Listener capabilities
B-1