LogProc

 IDLE

Request Accepted

by

Tag

?

Legend

:

Alternate Behavior

Normal Behavior

Precondition

: Tag

data has changed

REQUEST

Tag

 STATUS

Software Timer

Times Out

Yes

LogProc

 SCANS

DATA

Data

Changed?

Flag Data for

Transfer

to

LogDB

Tag

SENDS ALARM

Note:  Text shown

bold

 is a sub-system

Software Timer

Timing

No

Tag

 Offline

Tag

SENDS DATA

Low

Battery

Loop Until

All

Tags

Have

Been

Polled

DISPLAY ON

 GUI

PROGRAMMING

Tag

Done

No

Continue

Scanning

Store

Local

Yes

All Data Scanned?

No

Yes

UPDATE

LogDB

Update Request

From

LogDB

Figure 5: Activity Diagram For Update Database Use Case