Operating Instructions

Glossary
Siemens Building Technologies, Inc. 45
Glossary
A
Asynchronous mode
In this mode, the OPC Data Manager can submit multiple write requests to the Insight OPCServer without
having to wait for the “Write was Successful” signal from the OPCServer. During times of extended,
numberous COVs, this can cause a problem, in which the COV data backs up and the processing time
increases for each new COV.
B
bi-directional
Information can be transmitted in two directions—from the Master OPC item to the Slave OPC item, and
vice versa.
BLN
Building Level Network. A peer-to-peer communication trunk connecting Insight workstations and field
panels in the building control system.
C
COM
Component Object Model. Microsoft Corporation's binary specification that describes what an object is,
how it manages its lifetime, and how it tells the outside world what it can do.
COV
Change-Of-Value. Point trending method where each change in a point’s value, based on a pre-defined
limit, is recorded.
D
DCOM
Distributed Component Object Model. An extension of the Component Object Model (COM) to support
objects distributed across a network. DCOM was developed by Microsoft Corporation.
DLL
Dynamic Link Library. A library of executable functions or data that can be used by a Windows
application. DLL files usually end with the extension .dll, .exe, .drv, or .fon. A DLL can be used by
several applications at the same time. Some DLLs are provided with the Windows operating system and
available for any Windows application. Other DLLs are written for a particular application and are loaded
with the application.
H