Download User Manual SP232 Serial Extended Function Module (for 1502B/C

Parallel Protocol
i-j
j-k
j-l
i-l
h-k
1 < x < 50 microseconds
1 < x < 100 microseconds
150 < x < 200 microseconds
150 < x < 200 microseconds
150 < x < 200 microseconds
If the directive is to wait until signaled, the device should release the
/IR line at once and not assert it again until it sees another/IA strobe.
When the strobe is seen, the device may request attention by
asserting the /IR signal again.
If the directive is to reset, the device should release the /IR line at
once and not assert it again until it has cleared all errors, partial
frames and at least 20 milliseconds has passed for the instrument to
also get into a reset state.
Software Protocol
The software protocol is based on a master/slave relationship that
must exist between the instrument and the Option Port device. Since
the actual data acquisition routines in the instrument cannot be
interrupted, the instrument will provide service to the Option Port on
a polled basis. The polling frequency will be determined by how
much acquisition and display time is taken by the commands
accepted for execution through the Option Port in most circumstances. There are a number of levels of remote operation of the
instrument possible through the Option Port.
The first level is simply monitoring the instrument control settings
and requesting data from time to time. In this mode the instrument
operates normally (always acquiring) except for the small pieces of
time required to respond to queries from the Option Port device. This
mode is useful for manually setting the acquisition parameters and
capturing the data for archive or processing by the Option Port
device. This mode has the poorest Option Port response characteristic because most of the time is spent acquiring and displaying data in
normal operation.
The second level of operation is taking complete remote control of
the instrument. In this mode the instrument front panel is locked out
(the front panel controls may still be monitored). The instrument
6–8
SP232 User Manual