6482-901-01 Rev. A / August 2012
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Model 6482 Dual-Channel Picoammeter / Voltage Source Reference Manual
Section 12: Remote Operations
SPE, SPD (serial polling)
Use the serial polling sequence to obtain the Model 6482 serial poll byte. The serial poll byte
contains important information about internal functions. See
. Generally, the serial
polling sequence is used by the controller to determine which of several instruments has
requested service with the SRQ line. However, the serial polling sequence may be performed at
any time to obtain the status byte from the Model 6482.
Front-panel GPIB operation
This section describes features of the front panel that are part of GPIB operation, including
messages, status indicators, and the LOCAL key.
Error and status messages
for a list of status and error messages associated with IEEE-488 programming.
The instrument can be programmed to generate
a service request (SRQ)
, and command queries
can be performed to check for specific error conditions.
GPIB status indicators
The REM (remote), TALK (talk), LSTN (listen), and SRQ (service request) indicators show the
GPIB bus status. Each of these indicators is described below.
REM
This indicator shows when the instrument is in the remote state. REM does not necessarily
indicate the state of the bus REN line, because the instrument must be addressed to listen with
REN true before the REM indicator turns on. When the instrument is in remote operation, all
front-panel keys, except for the LOCAL key, are locked out. When REM is turned off, the
instrument is in the local state, and front-panel operation is restored.
NOTE
If local lockout (LLO) is in effect, LOCAL will be locked out. OUTPUT ON/OFF is still
operational in remote mode. If ARM:SOUR is set to manual, the TRIG key will be active
during remote operation.
TALK
This indicator is on when the instrument is in the talker active state. Place the instrument in the
talker state by addressing it to talk with the correct MTA (my talk address) command. TALK is off
when the instrument is in the talker idle state. Place the instrument in the talker idle state by
sending a UNT (untalk) command, addressing it to listen, or sending the IFC (interface clear)
command.
LSTN
This indicator is on when the Model 6482 is in the listener active state, which is activated by
addressing the instrument to listen with the correct MLA (my listen address) command. LSTN is off
when the instrument is in the listener idle state. Place the instrument in the listener idle state by
sending UNL (unlisten), addressing it to talk, or sending IFC (interface clear) command over the
bus.
SRQ
You can program the instrument to generate a service request (SRQ) when one or more errors or
conditions occur. When this indicator is on, a service request has been generated. This indicator
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