National Instruments NI-488.2M Software Reference Manual page 142

Appendix A Status Word Conditions
LACS (brd)
LACS indicates whether the GPIB board is addressed as a Listener. LACS is set
whenever the GPIB board detects its listen address (and secondary address, if
enabled) has been sent either by the GPIB board itself or by another Controller.
LACS is also set whenever the GPIB board shadow handshakes as a result of the
ibgts function. LACS is cleared whenever the GPIB board detects the
Unlisten (UNL) command, its own talk address, Interface Clear (IFC), or ibgts
is called without shadow handshake.
DTAS (brd)
DTAS indicates whether the GPIB board has detected a device trigger command.
DTAS is set whenever the GPIB board, as a Listener, detects the Group Execute
Trigger (GET) command has been sent by another Controller. DTAS is cleared
on any call immediately following an ibwait call if the DTAS bit is set in the
ibwait mask parameter.
DCAS (brd)
DCAS indicates whether the GPIB board has detected a device clear command.
DCAS is set whenever the GPIB board detects the Device Clear (DCL)
command has been sent by another Controller or whenever the GPIB board as a
Listener detects the Selected Device Clear (SDC) command has been sent by
another Controller. DCAS is cleared on any call immediately following an
ibwait call if the DCAS bit was set in the ibwait mask parameter, or on any
call immediately following a read or write.
© National Instruments Corp. A-5 NI-488.2M SRM for OS/2