Controller Programming; Front Panel Aspects Of Ieee-488 Operation; Front Panelerror Messages; Table 4-5 Hp Basic 4.0 Ieee-488 Statements - Keithley 486 Instruction Manual

SEClTON 4
IEEE-488 Reference
3. To change the primary address, use the rotary knob
ortheADJUST(+) todisplay the desired address.
4. To store the new address in memory, press MENU.
The next menu selection (defaults) will be displayed.
5. Exit from the menu by pressing SHIFI and then
M-FNJ.
NOTE
Each device on the bus must have a unique
mimarv address. Failure to observe this ore-
hio~will probably result in erratic bus'op-
eration.
4.6 CONTROLLER PROGRAMMING
The programmill g instructions covered in this section
use examples written with Hewlett Packard BASIC ver-
sion 4.0. This language was chosen because of its versatil-
ity in controlling the IEEE-488 bus. This section covers
those statements that are essential to Model 486/487 op-
eration.
NOTE
Contder programming information for us-
ing the IBM PC interfaced through the Capital
Equipment Corporation (CEC), I/OTech, and
National IEEE-488 interfaces is located in Ap-
pendiv D.
A partial list of
HP
BASIC 4.0
statements is
shown in
Table 4-5. The statements have a one or three digit argu-
ment that must be specified. The first digit is the interface
select code, which is set to 7 at the factory. The last two
digits
of
those statements requiring a
3-digit srgument
specify the primary address.
Those statements with a S-digit argument show a pri-
mary address of 22 (the factory set primary address). For
a different address, you would, of course, change the last
two digits to the required value. For example, to send a
GTL co mmand to a device using a primary address of 17,
the following statement would be used: LOCAL 717.
Some of the statements have two forms; the exact con-
figuration depends on the command to be sent over the
bus. For example, CLEAR 7 sends a DCL command,
while CLEAR 722 sends the SDC command to a device
with a primary address of 22.
Table 4-5. HP BASIC 4.0 IEEE-488 Statements
Transmit string to device 22.
Obtain string from device 22.
Send GTL to device 22.
Send SDC to device 22.
Send DCL to all devices.
Send remote enable.
Cancel remote enable.
Serial poll device 22.
Send local lockout.
Send GTL to device 22.
BASIC Statement
OUTPUT 722;A$
ENTER 7Z!;A$
LOCAL 727.
CLEAR 722
CLEAR 7
REMOTE 7
LOCAL 7
SPOLL (722)
LOCAL LOCKOUT 7
TRIGGER 722
ABORT 7
4.7 FRONT PANEL ASPECTS OF
IEEE-466 OPERATION
The following paragraphs discuss aspects of the front
panel that are part of IEEE-488 operation, including mes-
sages, status indicators, and the LOCAL key.
4.7.1 Front Panel Error Messages
Table 4-6 summarizes the front panel error
messages
as-
sociated with IEEE-488 programming. Note that the in-
stnunentmaybeprogrammedtogenerateanSRQ,andLJ
command status words can be checked for specific error
conditions if any of these errors occur. See paragraph5
42.11 and 42.19.
The following paragraphs describe the front panel
mes-
sages associated with IEEE-488 programming.
IDDC (Illegal Device-Dependent Command) Error
An IDDC error occurs when the unit receives an illegal
device-dependent command over the bus. For example,
the command string IX includes an illegal command be-
cause '?" is not part of the insbumenVs programming
language. When an illegal command is received, the in-
strument briefly displays the IDDC error message.
NOTE
When an IDDC error is detected in a com-
mand string, all commands in the string, up to
and including the next X, are ignored.
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