Product Manual

Remote Operation
GPIB Interface17
17-7
GPIB Subsets
This instrument contains the following IEEE 488.1 subsets:
Source Handshake SH1
Acceptor Handshake AH1
Talker T6
Listener L4
Service Request SR1
Remote Local RL1
Parallel Poll PP1
Device Clear DC1
Device Trigger DT1
Controller C0
Electrical Interface E2
GPIB IEEE Std. 488.2 Error Handling
The IEEE 488.2
UNTERMINATED error (addressed to talk with nothing to say) is
handled as follows. If the instrument is addressed to talk and the response formatter is
inactive and the input queue is empty then the
UNTERMINATED error is generated.
This will cause the Query Error bit to be set in the Standard Event Status Register, a
value of 3 to be placed in the Query Error Register and the parser to be reset .
The IEEE 488.2 INTERRUPTED error is handled as follows. If the response formatter
is waiting to send a response message and a
<PROGRAM MESSAGE TERMINATOR>
has been read by the parser or the input queue contains more than one END message
then the instrument has been
INTERRUPTED and an error is generated. This will cause
the Query Error bit to be set in the Standard Event Status Register, a value of 1 to be
placed in the Query Error Register and the response formatter to be reset thus clearing the
output queue. The parser will then start parsing the next
<PROGRAM MESSAGE UNIT>
from the input queue.
The IEEE 488.2 DEADLOCK error is handled as follows. If the response formatter is
waiting to send a response message and the input queue becomes full then the instrument
enters the
DEADLOCK state and an error is generated. This will cause the Query Error
bit to be set in the Standard Event Status Register, a value of 2 to be placed in the Query
Error Register and the response formatter to be reset thus clearing the output queue. The
parser will then start parsing the next
<PROGRAM MESSAGE UNIT> from the input
queue.
The section below on Status Reporting provides further information on these three error
handling processes.
GPIB Parallel Poll
Complete parallel poll capabilities are offered on this generator. The Parallel Poll Enable
Register is set to specify which bits in the Status Byte Register are to be used to form the
ist local message. The Parallel Poll Enable Register is set by the
*
PRE <nrf>
command and read by the
*
PRE? command. The value in the Parallel Poll Enable
Register is ANDed with the Status Byte Register; if the result is zero then the value of
ist
is 0; otherwise the value of ist is 1.
The instrument must also be configured so that the value of
ist can be returned to the
controller during a parallel poll operation. The instrument is configured by the controller
sending a Parallel Poll Configure command (PPC) followed by a Parallel Poll Enable
command (PPE).