Gpib; Calibration - Keithley 2002 User Manual

Front Panel Operation

2.12.2 GPIB

The GPIB menu is used for the following operations:
• To view or change the IEEE-488 address.
• To select the talk-only mode and its parameters.
• To select the data elements to send.
• To view the status byte of the instrument.
Changing between "Addressable" and "Talk-only" causes
triggers to be halted.
ADDRESSABLE
With the instrument set for "Addressable", it can listen and
talk to a bus controller. This menu item lets you check and/
or change the IEEE-488 address of the instrument. At the
factory the address is set to 16, but it can be changed to any
value from 0 to 30.
After selecting ADDRESSABLE, the present IEEE-488
address will be displayed. If you wish to change the address,
use the RANGE and keys to display the desired number
and press ENTER.
TALK-ONLY
In the talk-only mode, the Model 2002 ignores commands
from the bus and merely outputs data, as requested by the
printer. When the instrument is in the talk-only mode, the
TALK annunciator turns on.
The options for TALK-ONLY are explained as follows:
FEED: This item has options that select the type of readings
printed: readings after a math operation is performed
(AFTER-MATH), readings before a math operation
(BEFORE-MATH), or no readings (NONE).
INTERFACE: With the IEEE-488 option of this item, data
elements are sent to an IEEE-488 bus printer set for listen
always. With the CENTRONICS option, data elements are
sent to a printer with a Centronics (parallel) interface. The
printer must be connected with a Model 8530 IEEE-488 to
Centronics Printer Adapter Cable.
INTERVAL: The INTERVAL option controls how often
readings are printed (expressed as 1 out of nnnn readings).
FORMFEED: Use the FORMFEED option of the menu to
enable or disable the sending of a formfeed character to the
printer after printing a user-selectable number of lines per
page (1-255 lines).
2-96
ELEMENTS
This menu item lets you select the data elements sent:
• Reading The numeric value of the reading.
• Units The units of the reading.
• Reading# The buffer location of the reading. The
reading number can be reset to zero from the GEN-
ERAL MENU (see paragraph 2.12.7).
• Chan# The channel number on which the reading
was taken.
• Timestamp The real-time or relative timestamp for
each reading. Timestamp type is selected from the
GENERAL MENU (see paragraph 2.12.7).
• Status The reading status information (normal read-
ing, measurement overflow, relative reading).
STATUS
Use this menu item to view the IEEE-488 status byte. Refer
to Section 3 (IEEE- 488 Reference) for information on the
status byte.
The bits in the status byte are refreshed by exiting and re-
entering its menu.

2.12.3 CALIBRATION

The CALIBRATION menu is used for the following
operations:
• To perform comprehensive calibration.
• To perform point calibration.
• To view or change the calibration date.
Some of the menu items are locked to prevent unintended
changing of calibration constants.
COMPREHENSIVE
The procedure for comprehensive calibration is locked; to
enable it requires the CAL switch to be pressed. The proce-
dure uses accurate calibration equipment to supply precise
DC voltages, DC currents and resistance values. Refer to the
Model 2002 Calibration Manual for instructions.
POINT-CALS
This menu item is used to perform calibration for selected
functions. AC calibration requires no external equipment and
can be performed by the operator at any time to ensure the
accuracy of ACV and ACI measurements.