ProSoft Technology MVI56-AFC - Manual (Page 141)

MVI56-AFC ♦ ControlLogix Platform Events
Liquid and Gas Flow Computer User Manual
ProSoft Technology, Inc. Page 141 of 316
February 25, 2011
9.8 Special Events
Tag Rkv Description
0 - Never Used
Value: Always 0.
Notes: This entry in the Event Log has never been written.
The number of such entries starts at 1999 upon cold start and
decreases as events are written until none remain, after which oldest
events are overwritten with new ones.
1 - Event Log Download
Value: Number of last-downloaded event.
Notes: Triggered by a purge of the Event Log, which marks older events
as available to be overwritten by new ones.
2 - Cold Start
Value: Always 0.
Notes: This event is obsolete and is never written.
3 (1) Power-Up
Value: "Old" value is the last-saved wallclock from the previous session;
"new" value is always 0 (clock not yet set).
Notes: The last event written upon restart of the application and before
entering the meter scan. This event may be preceded by Checksum
Alarm and/or PLC Mode Change events.
4 - PLC Mode Change
Value: PLC mode (0 on line, 1 off line).
Notes: Logs changes to PLC connectivity as reported by the backplane
procedures. Typically caused by switching the PLC between "run" and
"program" modes.
5 - Checksum Alarm
Value: Checksum alarm word (datum type "Bsht").
Notes: Logs changes to the checksum alarm bitmaps.
Includes site/meter identification (bits 28-24).
Upon power-up:
Written automatically upon power up when a checksum failure is
detected. In this case the event is written even if the bitmap does not
change, such as when an affected bit is already set from a previous
failure that was never cleared.
Upon Modbus write to the bitmap:
Records changes to the bitmap only, typically when clearing bits, though
setting bits is also permitted.
6 (2) Wallclock Change
Value: Wallclock (packed bitfields).
Notes: Triggered when the wallclock is set for the first time, or when it is
reset to a value that differs from its current value by five minutes or
more. These two cases can be distinguished by the "old value" in the
event entry: for the initial setting this value is zero ("clock not set").
7 * Stream Select
Value: Stream number.
Notes: Triggered by a "select active stream" meter signal.
Includes meter identification (bits 28-24).