6 how do i... use relay outputs, 7 how do i... span subnets with a bbmd, I... u – Obvius BACnet User Manual

Page 36: Elay, Utputs, I... s, Ubnets with a, Bbmd, Span, Ip subnets

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BACnet Server for AcquiSuite

Page 36 of 52

CVS:bacnet/Documentation/BACnet_Users_Guide.doc

If non-standard unit abbreviations have been entered, the AcquiSuite will warn of Unit

Issues.

Click "View Log" to see each unit issue; correct the units of the meter and point in question.

Note: In all cases, the value of the data point will be correct even if its units cannot be

translated. Untranslatable units are encoded as dimensionless values (i.e., as a pure number). This

allows new unit-translations to be added in the future without disrupting existing applications.

7.6 How Do I... Use Relay Outputs?

The following relays are supported:

· Obvius, A8812 Internal I/O

· Obvius, A8332-8F2D Flex I/O

· Advantec, Adam 4068 and 4069

· Acromag, 902MB

· Coyote DataComm, Rio-9F

· Benjamin Electric, Power Panel Plus

Relays are modeled as BACnet Binary Value objects.

They are not "commandable" (i.e., they have no Priority_Array property).

In other words, the last write to the relay "wins".

Reading the Present_Value property of a Binary Value object returns the current state of the relay, which

may be different than the last written value if the relay was changed by some means outside of BACnet

(e.g., manual switch, Modbus/TCP write, AcquiSuite’s web UI, power cycling, etc.)

Note 1:

Some controllers such as the Tridium JACE assume Binary Value objects are read-

only. After discovering the relay's Binary Value object, you must change the JACE’s point to be

of type "BinaryWritable" so the JACE will write to it.

Note 2: Some controllers allow setting limits on how frequently a relay is changed. This feature of

the controller can give the impression that the relay is not functioning, when in fact, writes are

being throttled.

7.7 How Do I... Span Subnets with a BBMD?

The BBMD feature lets you place the AcquiSuite on an IP subnet different from the one containing your

BACnet controller.

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