Stanford Research Systems SR620, Manual

Page: 57 / 124

Programming Commands 41
SR620 Universal Time Interval Counter
byte enable register set) in their respective status
registers is set. They are not cleared until the
condition which set the bit is cleared. Thus, these
bits give a constant summary of the enabled
status bits. A service request will be generated
whenever an unmasked bit in the serial poll
register is set. Note that service requests are only
produced when the bit is first set and thus any
condition will only produce one service request.
Accordingly, if a service request is desired every
time an event occurs the status bit must be
cleared between events.
Standard Event Status Byte:
bit name usage
0
OPC Set by OPC command
when all operations are
complete
1 unused
2 Query Error Set on output queue
overflow
3 unused
4 Execution err Set by an out of range
parameter, or non-
completion of some
command due a condition
like overload.
5 Command err Set by a command syntax
error, or unrecognized
command
6 URQ Set by any key press or
trigger knob rotation
7 PON Set by power on
This status byte is defined by IEEE-488.2 (1987)
and is used primarily to report errors in commands
received over the communications interfaces. The
bits in this register stay set once set and are
cleared by reading them or by the *CLS command.
TIC Status Byte:
bit name usage
0
Ext Trig Set when the external
trigger comparator switches
1 A trig Set when the A channel
trigger comparator switches
2 B trig Set when the B channel
trigger comparator switches
3 arm Set when the SR620
becomes armed
4 Ext Ovld Set by Ext input overload
condition
5 A Ovld Set by A input overload
condition
6 B Ovld Set by B input overload
condition
7 unused
These bits stay set until cleared by reading or by
the *CLS command.
Error Status Byte:
bit name usage
0
print error Set when an error is
detected during
printing/plotting
1 no clock Set when the 10 MHz clock
signal is not present
2 A autolevel Set when A channel
autolevel looses the trigger
and tries to find a new
trigger level.
3 B autolevel Set when B channel
autolevel looses the trigger
and tries to find a new
trigger level.
4 test error Set when the self test
routine detects an error
5 cal error Set when the auto cal
routine detects an error
6 warmup Set when unit is warmed up
after power on
7 ovfl/div0 Set when internal counters
overflow or on ratio mode
divide by 0
These bits stay set until cleared by reading or by
the *CLS command.