Digital Output BACnet Objects

BO - Digital Output Object Description

Each of the digital outputs in all types of modules is represented on the BACnet network as the BACnet Binary Output object with the following properties.

Dynamically creatable: no, dynamically deletable: no.

Note: Additional properties of the object are saved to maintain the backward compatibility with the older firmware version. In the new firmware version, each property has a corresponding BACnet object.

PRESENT_VALUE Property

The property contains the actual value of the digital output. If the DO is in the hand mode, the actual value of the DO is stored in both PRESENT VALUE property and HAND_STATUS object.

Digital Output COV

In the firmware versions above 4.0, multiprotocol I/O modules support COV (change of value). It means that the module automatically sends the digital output value with every change.

STATUS FLAG Property

The Status Flag property contains information about the status of the object. This property consists of 4 binary flags. Each flag is described in the table below.

OUT OF SERVICE Property

For digital outputs, the OUT OF SERVICE property is set to true if the output is overridden by the USB connection or from a module web page (only in IP version). In such case, the OUT OF SERVICE is set to false if the Present Value property is set by the BACnet message.

HAND_STATUS Object (Multistate Value: 23-26, 27-34 for MAX Modules)

The property stores information about the status of the hand operation switch and the status of the DO in the hand mode, according to the table below: