EM58 • HS58 • HM58 POWERLINK
XDD files are paired with the
Lika.bmp
picture file available inside the file
folder.
www.lika.biz > ROTARY ENCODERS > ABSOLUTE ENCODERS
to download the XDD files from Lika's corporate web site.
6.11 Communication objects
POWERLINK uses the same device description files as CANopen, the same Object
Dictionaries and the same communication mechanisms, such as Network
Management (NMT), Process Data Objects (PDO) and Service Data Objects (SDO).
Three main kinds of communication messages are used in a POWERLINK
network:
Network Management NMT
protocol: NMT protocols are used to issue
state machine change commands (i.e. to start and stop the devices), detect
remote device boot-ups and error conditions.
Process Data Objects PDO
protocol: used to process real time data
(transmission of process data in real time).
Service Data Objects SDO
protocol: used to set and read values from the
Object Dictionary of a remote device in the asynchronous phase.
6.11.1 NMT Network Management
POWERLINK Network Management (NMT) is node-oriented and follows a
Master/Slave relationship. The function of the NMT Master is carried out by the
MN.
•
NMT State Command Services
. The MN uses NMT State Command
Services to control the CN state machine(s), see the “6.9 CN Node NMT
States” section on page 66.
•
NMT Managing Command Services
. The MN uses NMT Managing
Command Services to access NMT data items of the CN(s) in a fast
coordinated way.
•
NMT Response Services
. NMT Response Services indicate the current
NMT state of a CN to the MN.
•
NMT Info Services
. NMT Info Services are used to transmit NMT
information from the MN to a CN.
•
NMT Guard Services
. NMT Guard Services are used by the MN and CNs
to detect failures in a POWERLINK network.
A CN may request NMT command and info services to be issued by the MN.
NMT services are defined in the Communication Profile Area of the Object
Dictionary, refer to the “6.12 Object Dictionary” section on page 72.
MAN EM58_HS58_HM58 PL E 1.1.odt
POWERLINK interface
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