Obvius BACnet - Manual (Page 49)

BACnet Server for AcquiSuite Page 49 of 52
CVS:bacnet/Documentation/BACnet_Users_Guide.doc
Each Device Object is assigned a Device ID number, from 0 to 4194302 (a 22-bit number, 2 22 -2), which
must be unique across the BACnet network.
Each Device Object is also assigned a name.
These two properties, Device ID and Device Name, are used to look up a device's BACnet address, much
like a hostname is used to look up an IP address.
9.2 Background on "Analog Input Objects"
A BACnet Analog Input Object represents a single data point on a meter.
These are numbered starting from 1: AI1, AI2, AI3, ... where AI1 = Point 1, AI2 = Point 2, etc.
Unlike Modbus, where registers may have several formats (integer, unsigned, float, little-endian, big-
endian, etc.), Analog Input Objects always provide data in a single IEEE float format.
9.3 Background on "Binary Value Objects"
A BACnet Binary Value Object represents a digital flag with a value of either 0 or 1.
If the meter has relay outputs, for each relay, the AcquiSuite creates one Binary Value Object. The
name of the object is suffixed with " Relay".
9.4 Terminology: PICS, EPICS and BIBBs
PICS = BACnet "Protocol Implementation Conformance Statement". This is a "BACnet spec sheet" in a
standard format.
EPICS = Electronic PICS. This is a more precise, machine-readable version of the PICS.
BIBB = BACnet Interoperability Building Block. This is a fancy way to describe a collection of related
protocol features. Each class of BACnet device is expected to implement certain BIBBs in order to be
certified.