CARLO GAVAZZI VariFlex3 RVLF Series User Manual

Motor Controllers AC Variable Frequency Drives Type VariFlex
3
RVLF
Specications are subject to change without notice. Pictures are just an example. For special features and/or customization, please ask to our sales network. 13/12/2017 155
BACnet is the communication protocol by way of protocol stack so the pocket is composed of stacked
layer types. Refer to the following figure.
When application program sends the BACnet service request for the pocket, it requires requesting
for executing BACnet request program in the application layer via application program interface. The
requirements of the program are sent to the application layer and application protocol data unit (APDU)
consists of Application Protocol Control Information (APCI) and Servie Data of application program. Then
APDU passes its messages downward to BACnet request program in the network layer. APDU becomes
Network Layer Protocol Data Unit (NPDU) composed of Network Service Data Unit (NSDU) and Network
Protocol Control Information (NPCI). And so forth for the data link layer and physical layer to complete the
full service for the packet.
2. BACnet Protocol Structure
Application
Layer
Network Layer
Data Link Layer
Physical Layer
Application Layer of BACnet
Network Layer of BACnet
ISO- 8802-2
(IEEE802.2)
ISO- 8802-3
(IEEE802.3)
ARCNET
MS/TP PTP
EIA-485 EIA-232
LonkTal
k
OSI Corresponding ModelBACnet Simple Model
Request
for PDU
Respond
to PDU
Receiv
e
Send
Receiv
e
Send
R
equest Respond
Client Server
Application
Program
Object
Object
Object
Object
BACnet Device
Request for
Service
Respond to
Service
Network
Service request
Read property
Service Reply?
BACnet Service
Request
Application Program
Application Layer
Network Layer
Data Link Layer
Physical Layer
A-BACnet.Request
N-UNITDATA.Request
DL-
UNITDATA.Request
MA-
UNITDATA.Request
P-UNITDATA.Request
APCI
Service
Data
APDU
NSDUNPCI NPDU
LSDU LPDULPCI
MSDUMPCI
PSDUPPCI
MPDU
PPDU
Application
Layer
Network Layer
Data Link Layer
Physical Layer
Application Layer of BACnet
Network Layer of BACnet
ISO- 8802-2
(IEEE802.2)
ISO- 8802-3
(IEEE802.3)
ARCNET
MS/TP PTP
EIA-485 EIA-232
LonkTal
k
OSI Corresponding ModelBACnet Simple Model
Request
for PDU
Respond
to PDU
Receiv
e
Send
Receiv
e
Send
R
equest Respond
Client Server
Application
Program
Object
Object
Object
Object
BACnet Device
Request for
Service
Respond to
Service
Network
Service request
Read property
Service Reply?
BACnet Service
Request
Application Program
Application Layer
Network Layer
Data Link Layer
Physical Layer
A-BACnet.Request
N-UNITDATA.Request
DL-
UNITDATA.Request
MA-
UNITDATA.Request
P-UNITDATA.Request
APCI
Service
Data
APDU
NSDUNPCI NPDU
LSDU LPDULPCI
MSDUMPCI
PSDUPPCI
MPDU
PPDU

CARLO GAVAZZI VariFlex3 RVLF Series Specifications

General

Brand	CARLO GAVAZZI
Model	VariFlex3 RVLF Series
Category	Controller
Language	English