Operating Instructions

Chapter 4 – Configuring Groups, Shared Points, and Statistics
32 Siemens Building Technologies, Inc.
Figure 6 shows the communication flow for a uni-directional point in which the point value is transferred
from a third-party system to the APOGEE Automation System. You should create this type of uni-
directional point for a third-party OPC item that you want to monitor, but not command, with Insight
software.
Figure 6. Third-party Output to APOGEE Input.
Bi-directional Points
In a bi-directional point, the value of the Master can always be transferred to the Slave. Also, the Slave
value can be transferred to the Master if all of the following apply:
• The new OPC item value does not match the OPC Data Manager point’s current value.
• The master item has updated the point at least once with a good value.
• The update is not the result of a refresh request.
The rules prevent data from bouncing back and forth between the Master and Slave, and also prevent the
Slave from contaminating the Master value before the Master has a chance to write to the Slave.
You should create a bi-directional point for a third-party OPC item that you want to monitor and
command with Insight software.
Before You Begin
Before you begin adding shared points, be sure that virtual points have been created via Insight software
to hold shared point values. For information about creating virtual points, see the Insight Point Editor
online help.
Adding Shared Points
After a group has been created, you can add shared points. Table 5 summarizes the options that you have
for configuring shared points.
Table 5. Options for Shared Point Configuration.
If you want to: Then create a:
Set and command the value of an OPC
item on a third-party server.
Uni-directional point that has a physical or virtual point as
its Master (input) and a third-party OPC item as its Slave
(output).
Only view the value of an OPC item on
a third-party server.
Uni-directional point that has a third-party OPC item as its
Master (input) and a virtual point as its Slave (output).