Bacnet Object Function - Mitsubishi Electric MELSEC iQ-F Series User Manual

4.2

BACnet Object Function

This function is used for using a programmable controller system as a BACnet device.
By registering objects to the Ethernet module, various services can be sent to/received from a BACnet workstation and
BACnet controllers.
Some of the properties of an object are assigned to the data assignment area in the buffer memory and can be accessed from
a program.
Objects are registered with GX Works3. ( Page 53 BACnet function setting)
The following figure shows how a BACnet workstation reads an analog value from the AnalogInput object (instance number:
0) of the Ethernet module.
Programmable
*1
controller system
FX5-4AD-ADP
FX5 CPU module
CH1
12345
(2) (2)
*1 The programmable controller system communicates as a BACnet device.
*2 AnalogInput object is an object that reads analog values from a programmable controller to a BACnet workstation.
(1) Connect a personal computer to the Ethernet module and register the AnalogInput object (instance number: 0) with GX Works3.
(2) Read an analog value from the FX5-4AD-ADP using the program of the FX5 CPU module.
(3) Write the analog value read using the program to the PresentValue property of the AnalogInput object registered in (1).
(4) The value of the PresentValue property in the buffer memory of the Ethernet module is reflected in the PresentValue property in the internal memory.
(5) The BACnet workstation sends a service to read the PresentValue property of the AnalogInput object in the Ethernet module.
4 FUNCTIONS
20
4.2 BACnet Object Function
Buffer memory
AnalogInput object
(Instance number: 0)
Program
Property value
D0 PresentValue
12345
(3) (3)
(1)
Ethernet module
Internal memory
*2
AnalogInput object
(Instance number: 0)
Property value
12345
(4)
*2
BACnet workstation
PresentValue
12345
(5)
12345