Siemens SIMATIC PCS 7 OSx, Operator'S Manual, Page: 38 / 232

OSx Station Basics
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SIMATIC PCS 7 OSx 4.1.2 Operator
OSx Operation Station Restrictions (continued)
It is possible for the action request icon to be blinking on one OSx station,
but not blinking on another station. This can occur when all the following
events take place:
•
A user is logged in at station A.
• OSx is set to the Operate state.
• An action request is triggered and the action request icon at station A
begins to blink.
• The user at station A clicks on the action request icon, causing it to
stop blinking.
• Another user, whose user ID is in the same process group as that of the
action request, then logs in at station B.
When the second user logs in, the action request icon on station B will be
blinking. No corrective action is necessary.
When a deadband is assigned to a networked tag, the system ignores any
changes in the value of the tag that are less than the deadband value. This
means that the database for each OSx station can potentially have differing
values (up to the deadband value) for the same attribute. When the
deadband is set to zero, the system updates the database with every change.
This can have an adverse effect on system performance.
If you open a session from an X terminal after the prompt to designate a
new primary has already appeared on the OSx host station, the prompt does
not appear on the X terminal. To verify from the X terminal that the host
station is communicating with the primary, check Network Status.
Action Request
Display
Assigning
Deadband Values
X Terminals and
Loss of Primary