Coni'roller Programmin G; Controller Handler Software; Model 595 Interface Function Codes - Keithley 595 Instruction Manual

IEEE-488 PROGRAMMING
nectar. The codes define Model 695 capabilities as fOl.lows:
SH (Source Handshake Function)-SHl defines the ability
of the instrument to initiate the transfer Of mesSage/data
over the data bus.
AH (Acceptor Handshake Function)-AH1 defmes the
ability of the instrument to guarantee proper reception Of
message/data transmitted over the data bus.
T (Talker Function)-The abiIity of the instrument to send
data-over the bus to other devices is provided by the T func-
tion (T5). Instrument talker capabilities exist only after the
instrutient has been addressed to talk, or when it has been
placed in talk only.
SHl
AH1
T5
LA
SRI
RIJI
IT0
DC1
2i
El
TEO
LEO
1
suppoti various interface functions and should not be con-
Table 4-2. Model 595 Interface Function Codes
fused with programming commands found elsewhere in
this manual. The interface function codes for the Model
595 are listed in Table 4-2. These codes are also listed for
Interface Function
'convenience on the rear uanel adiacent to the IF33488 con-
Source Handshake capability
Acceptor Handshake capability
Talker (basic talker, serial poll, unaddressed
to talk on LAG)
Listener (basic listener, unaddressed to listen
on TAG) -~
Service Request capability
Some Remote/Local caoabiitv
No Parallel Poll capabiity '
Device Qear capability
Device Trigger capability
Some Controller capability
Open Collector Bus Drivers
No Extended Talker capabilities
No Extended Listener caoabiliti%
L (Listener Function)-The ability for the instrument to
receive device-dependent data over the bus from other
4.6 CONTROLLER PROGRAMMING
devices is provided by the L function (l-4). Listener
capabilities of the instrument exist only after it has been
addressed
to
listen.
SR (Service Request Function)-SR1 defines the abiIi@ of
the instrument to request service from the controller.
RL (Remote-Local Function)-The RL function defmes the
ability of the instrument to be placed in remote or local.
While the instrument is in remote, the front panel controls
are funaional unless LLO (local lockout) has been asserted.
PP (Parallel Poll Function)-The instrument does not have
parallel polling capabilities (PPO).
DC (Device Clear Function)-DC1 defines the ability of the
instrument to be cleared (initialized).
lX (Device Trigger Function)-The ability for the instrument
to have its readings triggered is provided by lYll.
C. (Coi+rolIer Function)-The instrument has some con-
troller capabilities (C28).
TE (Extended Talker Function)-The instrument does not
have extended talker capabilities (TEO).
LE (Extended Listener Function)-The instnunent does not
have extended listener capabilities (LEO).
E (BUS Driver Type)-The instrument has open-collector bus
drivers (El).
There are a number of IEEE-488 controllers available, each
with its own programming language. Also, different in-
struments have d&ring capabilities. In this section, we will
discuss programming languages for HP-85. In addition, in-
terface function codes that-define Model 595 capabilities
will be discussed.
NOTE
Controller programming information for using the
IBM-PC interfaced through a Keithley Model 8.5734
IEEE-488 interface is located in Appendi D. See
Appendix E for other controller programs.
4.6.1 Controller Handler Software
Before a specific controller can be used over the IEEE-488
bus, it must have IEEE488 handler software installed. With
some controllers, the software is located in ROM, and no
software initialization is required on the part of the user.
With other controllers, software must be loaded from disk
or tape and be properly initialized. With the Hp-85, for ex-
ample, an additional I/O ROM that handles interface func-
tions mu&be installed.
Other small computers that can be used as IEEE-488 con-
trollers may have limited capabilities. With some, interface
programming functions may depend on the interface be-
ing used. Often little software "tricks" are required to ob-
tain the desired results.
4-5