General Bus Commands; Ren(Remoteenable); Ifc (Interfaceclear); Table 4-4 Ieee Contact Designations - Keithley 486 Instruction Manual

SECTION 4
IEEE-488 Reference
4.3 GENERAL BUS COMMANDS
General bus commands are those commands such as
DCL that have the same general meaning regardless of
the instrument. Commands supported by the Model
486/487 are listed in Table 4-4 which also lists BASIC
statements necessary to send each command. Note that
commands requiring that a primary address be specified
assume that the primary address is set to 22. This is the
address that is set at the factory.
Table 4-4.
IEEE Contact Designations
COntaCt
IEEE-488
Number
Desiznation
:
3
4
2
r?
9
:;
12
:i
15
16
:i
ii
21
2
24
DIOl
DIO2
DI03
Data
Data
Data
DIO4
Data
EOI (24)'
Management
DAV Handshake
EZ
Handshake
Handshake
LFC
Management
SRQ
ATN
Management
Management
SHIELD Ground
DIO5
Data
DI06 Data
DIO7 Data
DIOS
Data
REbJ (24)'
Management
Gnd, (6)' Ground
Gnd, (7)'
Ground
Gnd, (8)' Ground
Gnd, (9)"
Ground
Gnd, (10)' Ground
Gnd, (11)'
Ground
Gnd, LOGIC Ground
TYPe
4.3.1 REN (Remote Enable)
ENTER 722; A$
The remote enable command is sent to the Model
486/487 by the controller to set up the instrument for re-
mote operation. Generally, the instrument should be
placed in the remote mode before you attempt to pro-
grsmitoverthebus.SimplysettingRENtruedoesnotac-
tually place the instrument in the remote state. Instead
the instrument must be addressed to listen after setting
REN true before it goes into remote.
Note that the instrument need not be in remote to be a
talker.
Programming Example - This sequence is automati-
cally performed by the controller when the following is
typed into the keyboard.
REMOTE 722
AftertheRETURNkeyispressed,theinstrumentisinthe
remote state, as indicated by the REM indicator. If not,
check to see that the instrument is set to the proper pri-
mary address 22, and c?xck to see that the bus comwc-
tions are properly made.
Note that all front panel controls except for LOCAL (and,
of course, POWER) are inoperative while the instrument
is in remote. You can restore normal front panel opera-
tion by pressing the LOCAL key.
4.3.2 IFC (Interface Clear)
The IFC command is sent by the con!xoller to place the
Model 486/487 in the talker and listener idle states. The
unit responds to the IPC comman d by canceling front
panel TALK or LISTEN lights, if the instrument was pre-
viously placed in one of those states.
To send the IFC command, the controller need only set
the IFC line true for a minimum of 100wec.
Programming Example-Before demonstrating the IFC
commend, turn on the TALK indicator with the follow-
ing statement
At this point, the TALK light should be on. The IFC com-
mand can be sent by entering the following statement
into the computer:
ABORTIO 7
4-44