+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1 | HEADER CHECKSUM |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
2 | TIME UNTIL DOWN |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
3 | DOWN DURATION |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
Figure 30 . LINK GOING DOWN
0[15] Message Type = 1 (Control Message).
0[14] Loopback Bit.
0[12-13] Go-Priority.
0[8-11] Reserved.
0[4-7] Reason. This field is used by the SIMP or the host
to indicate the reason for disabling this SIMP-host
link as follows:
0 = NOT going down: Cancel previous Link
Going Down message
1 = Unspecified reason
2 = Scheduled PM
3 = Scheduled hardware work
4 = Scheduled software work
5 = Emergency restart
6 = Power outage
7 = Software breakpoint
8 = Hardware failure
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RFC907 Host Access Protocol
July 1984 Specification
9 = Not scheduled up
10 = Last warning: The SIMP or host is disabling
the link in 10 seconds
11-15 = Undefined
0[0-3] Control Message Type = 7 (Link Going Down).
1[0-15] Header Checksum. Covers words 0-3.
2[0-15] Time Until Down. This field specifies the amount of
time remaining until the SIMP or host disables the
link (in minutes). An entry of zero indicates that
there is less than a minute remaining.
3[0-15] Down Duration. This field specifies the amount of
time that the SIMP-host link will be down (in
minutes). An entry of zero indicates that the down
duration will be less than a minute. An entry of -1
(all bits set) indicates an indefinite down duration.
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RFC907 Host Access Protocol
July 1984 Specification
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
0 | 1|LB| XXXXX | 6 |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
1 | HEADER CHECKSUM |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
2-N | ARBITRARY DATA |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
Figure 31 . NO OPERATION (NOP)
0[15] Message Type = 1 (Control Message).
0[14] Loopback Bit.
0[4-13] Reserved.
0[0-3] Control Message Type = 6 (NOP).
1[0-15] Header Checksum. Covers words 0-N.
2-N Arbitrary Data. Up to 32 words of data may be sent.
The data are undefined by HAP.