Measurement Computing Micro 488/EX rev.2.1 - Manual (Page 57)

Section 4 General Programming
4.15
IDLE This event occurs when the Micro488/EX, as a Peripheral
(*CA), transitions from a Talker or Listener state to an idle
state (neither talker or listener). It indicates that the
controller has unaddressed the Micro488/EX with either
an UNT or UNL command. This event is edge sensitive.
When the MACRO is executed, the internal status, as read
by the STATUS 1 command, is cleared. This event is
tested prior to the CHANGE event and will clear the
internal CHANGE status only when the addressed to un-
addressed transition occurs.
CHANGE This event occurs when the Micro488/EX, as a Peripheral
(*CA), detects an addressed state change. This occurs on
transitions from a Talker or Listener state to an idle state
(neither talker or listener), or from an idle state to a talker
or listener state. This event is edge sensitive. When the
MACRO
is executed, the internal status, as read by the
STATUS 1 command, is cleared. This event is tested after
the IDLE event. If IDLE is enabled, the CHANGE event's
Macro will only execute when an un-addressed to an
addressed transition occurs.
ERROR This event occurs when the Micro488/EX detects an error
condition. The error condition may be an un-recognized
command from the serial host, an invalid parameter or a
bus error. Refer to Appendix B for a listing of the error
conditions which can be detected by the Micro488/EX.
This event is level sensitive. When the MACRO executes,
the error status, as read by any of the STATUS
commands, must be read prior to enabling this event
again.
STARTUP This edge sensitive event occurs when the Micro488/EX is
powered on, upon the receipt of an ID character, double
ID
characters or RESET command. If a MACRO has been
assigned as a STARTUP macro, it sets LOG ON and
executes. This is the only event which cannot be re-
enabled within a MACRO. Although STARTUP is a valid
condition within the ARM command, it does not ARM.