Appendix C: Communication interface
Model 2110 5½ Digit Multimeter Reference Manual
C-10
2110-901-01 Rev. C/August 2013
DCL
Use the device clear (DCL) command to clear the GPIB interface and return it to a known state. Note
that the DCL command is not an addressed command, so all instruments equipped to implement DCL
will do so simultaneously.
When the Model 2110 receives a DCL command, it:
•
Clears the input buffer, output queue, and command queue
•
Cancels deferred commands
•
Clears any command that prevents the processing of any other device command
A DCL does not affect instrument settings and stored data.
SDC
The selective device clear (SDC) command is an addressed command that performs essentially the
same function as the device clear (DCL) command. However, because each device must be
individually addressed, the SDC command provides a method to clear only selected instruments,
instead of clearing all instruments simultaneously with the DCL command.
When the Model 2110 receives an SDC command, it clears the input buffer and output queue,
cancels deferred commands, and clears any command that prevents the processing of any other
device command. An SDC command does not affect instrument settings and stored data.
GET
The group execute trigger (GET) command is a GPIB trigger that triggers the instrument to take
readings from a remote interface.
SPE, SPD
Use the serial polling sequence to obtain the Model 2110 serial poll byte. The serial poll byte contains
important information about internal functions (see
(on page B-1)). Generally, the serial
polling sequence is used by the controller to determine which of several instruments has requested
service with the SRQ line. The serial polling sequence may be performed at any time to obtain the
status byte from the Model 2110.
GPIB status indicators
The ADR status indicator shows that the instrument is controlled via the GPIB Interface.
Configure the GPIB controllers
Each instrument on a GPIB bus needs a unique address from a range of 0 to 30. Generally, the GPIB
host controller is on address 0. However, there are GPIB controllers that adopt the address of 21. To
be safe, do not configure any of the instruments for 21 or 0.
If you do need to change the host controller address, consult the controller documentation.
For the KPCI-488LPA and KUSB-488B GPIB controller from Keithley Instruments, the configuration
utility is called the KI-488 Diagnostic Tool. It is available from the Microsoft
®
Windows
®
Start menu at
Keithley Instruments > KI-488 > KI-488 Diagnostic Tool
.
