User manual

Computer Gateway User Manual 4-30 5/96
4.4.5
4.4.5 Turn On ACP
This is the only unsolicited application-level message from the CG during normal operation
and is used to signal the need for a specified ACP to begin execution.
Eight-Character Tagname Form
Header information: Word 1—Transaction Code = 2
Word 2—Number of Words = 9
Word 5—CG Identifier = 1
Word 6—Host Task Identifier = DI
Message format: Words 1..4—ACIDP name (8 ASCII characters)
Word 5—OPER_DMD (integer) 0=OFF, 1=ON
Word 6—PPS (integer) 0=OFF, 1=ON
Word 7—TAKE_I_P (integer) 0=OFF, 1=ON
Word 8—SCHEDULED (integer) 0=OFF, 1=ON
Word 9—PS_MSG (integer) 0=OFF, 1=ON
Use information: The CG resets each of these values to OFF upon dispatch of this
message in order to prepare for the next "trigger" event (which
may occur while the ACP is running). The host processor must
provide for the event of this message arriving while the associated
ACP is executing.
The ACP needs to examine this data to determine why it was
activated. SCHEDULED is set ON whenever the ACP is to be
executed because of either CYCLIC or PERIODIC scheduling.
PS_MSG is set ON whenever a message for this ACP is being
held at the CG. PPS is defined at heading 2.2.1.3. OPER_DMD,
and TAKE_I_P are defined at paragraph 6.4.
The host processor reaction to this message should include
• Activation of the addressed ACP (passing to it the message
information contained in words 5 through 9.
• Dispatch of an ACIDP execution state change (to run) to the CG.