3-4
3
change state. The 4863/2363 can also monitor fifteen of the digital I/O lines
for changes with the Questionable Transition Registers. The lines are only
monitored if they are assigned as inputs. Detected input signal changes set
corresponding bits in the Questionable Event register. The register sum-
mary bit will appear in the Status Byte Register and if enabled, set the
Service Request bit, generating an SRQ. The user can serial poll or query
the Status Byte to determine the source of the SRQ and read the input data
by a command or through the Questionable register.
The 4863 provides multiple control and status and control lines for interfac-
ing with external digital devices. Output control signals include Trigger,
Reset, Remote, Clear and Data Strobe lines. Inputs include two general
purpose status lines that are inputted via the Operation Condition register
in the 488.2 Status Reporting Structure. The user can set the Status
Reporting Structure to monitor these lines and generate a SRQ when they
change state or periodically poll them by querying the Operation Condition
register.
At power turn on, the 4863 restores the last configuration and output values
stored in its Flash memory by the *SAV 0 command as the current
configuration. These values are used until a command is sent to the 4863
with a replacement value which then becomes part of the current configu-
ration. When power is turned off, the current configuration values are lost.
The *SAV 0 command must be sent to the 4863 to save the new current
configuration in the 4863's Flash memory. The user should set the 4863's
digital outputs to their correct power-on values before doing a *SAV 0
command. A lock function hides the configuration settings and prevents
changes to the configuration parameters when the lock function is enabled.
The GPIB address, address mode and Status Register settings are not
affected by the lock function.
3.2.2
2363 Differences
The 2363 is similar to the 4863 except that the 4863's GPIB interface is
replaced by a RS-232 and a RS-485 (RS-422) serial interfaces. The 2363's
operating functions and digital I/O commands are the same as those
described for the 4863 when operated in the single address mode.
The 2363 only transfers data as command parameters or in response to a
query and returns a 'prompt' when ready for the next command. GPIB SRQs
are replaced by a serial Service Request Message (SRM). The 2363's serial
