SICK DAX Threaded Kurzanleitung Seite 14

NMTs control the status of the network and individual components. They can
•
also be used for monitoring purposes using the following objects:
SYNC object:
°
The SYNC object synchronizes the bus communication, i.e. synchronous
PDOs are sent to the controller after a SYNC object is received.
° Emergency object:
The emergency object sends error messages. As they generally have a
higher priority than PDOs, these emergency objects will be transmitted
first.
° Nodeguard object:
The CANopen® linear encoder uses the node guarding protocol to per‐
form the error control services of the CANopen® network.
The bus master uses a remote frame to send a nodeguard message
to the CANopen® device, and in response the device reports its cur‐
rent NMT status using a standard nodeguard message. The nodeguard
frame format, and the NMT state value definitions are shown in the
following tables. The nodeguard protocol is activated as default.
6.3.5 CANopen State Machine
As in every CANopen® device, a socalled CANopen® state machine is imple‐
mented in the DAX® CANopen. A differentiation is made between the following
statuses:
Status of the CANopen® state machine
Status Description
Initializing The initialization starts. The device application and the device com‐
munication are initialized. Then the node switches automatically to
the Pre‐ operational status.
Pre-Operational DAX® is ready for configuration, acyclic communication can take
place via SDO. However, DAX® is not yet able to participate in PDO
communication and also does not send any emergency messages.
Operational In this status DAX® is fully operational and can transmit messages
independently (PDOs, emergency messages).
Stopped In this status DAX® is disabled for communication (active connection
monitoring via node guarding remains active).
6.3.6 Node Guard/Heartbeat-Protokoll
The heartbeat mechanism for a CANopen® device is implemented as a cyclic
transmission of the heartbeat message by the heartbeat encoder. One or more
CANopen® devices in the network support this heartbeat message. If the heart‐
beat cycle for the heartbeat encoder fails, the host is informed about this event.
The format for node guard/heartbeat frames and NMT state value definitions are
shown in the table below. The node guard message and the heartbeat message
differ only in the bit in the node guard protocol, unlike the heartbeat message,
used to change the state of the data MSB.
Node guard / heartbeat protocol message
Data
COB-
Rx/Tx DLC
ID
D0 D1
700h + Tx 1 STATE -
Node
ID
Node guard / heartbeat protocol data
STATE Meaning
00h Bootup
04h Stopped
05h Operational
7fh Pre-Operational
NOTE
The COB-ID can be read from the object dictionary using the index "100Eh".
The COB-ID of the boot-up message cannot be changed.
6.3.7 Configuration and system startup
After electrical connection to the network, the device is ready for commissioning
and configuration. Before actual system startup, the communication parameters
for operation need to be set in the CAN bus. Only the basic procedure is descri‐
bed in these operating instructions. Please refer to the "Technical information
(8028137)" for details on all the available commands for configuring the device
www.sick.com/DAX® can be found.
Setting the node parameters
To be able to operate the device in a CAN bus network, it is necessary to first
configure the network characteristics. The basic settings for integrating a bus sub‐
scriber are made using LSS (Layer Setting Services). Every device (node) in the
CAN network is uniquely identified by its LSS address. This address is composed
as follows:
LSS address
Vendor ID
Product code
Revision number
Serial number
8028139/1LXF/2023/12/01/de, en
D2 D3 D4 D5 D6
- - - - -
CANopen®
1000056h
According to the production key
According to the production key
Actual serial number of the CANopen®
encoder
Parameters specific to the CAN bus, such as baud rate and node ID, are also
configured and saved via the LSS service. Both the baud rate and node ID of
the encoder must be configured for operation in the specific CAN bus implemen‐
tation.
Setting the node ID
WARNING
When programming the node ID, only one device must be connected.
Every device must be assigned a number (node ID). This number is used to
identify the node within the CANopen® network. Each node ID must be unique.
The CANopen® node ID is in the range 1 - 127. To ensure error-free operation of
the network, the ID of every node in the CAN bus must be unique.
The node ID of the device can be set using the following command sequence:
Setting the node ID
Data source COB-ID
Controller 7e5h
Controller 7e5h
Sensor 7e4h
Node address values can be between 1 and 127 (e.g., 125)
1
A change in node address is effective immediately. To permanently save the node
address, the following command must be sent:
Saving the node ID
Data source COB-ID
Controller 7e5h
Sensor 7e4h
Setting the baud rate
The baud rate indicates the speed of operation of the device and also the entire
CAN bus. The device and entire network must be set to the same baud rate.
The maximum baud rate is limited by the cable length used for the CAN network
as a whole. The device is delivered with a preset, order-dependent baud rate. If
this baud rate needs to be changed, it can be configured via the LSS.
Baud rate as a function of cable length
Length of cable
< 25 m
< 50 m
< 100 m
< 250 m
D7
< 500 m
-
< 1,000 m
< 2,500 m
< 5,000 m
The baud rate can be set using the following commands:
Setting the baud rate
Data source COB-ID
Controller 7e5h
Controller 7e5h
Sensor 7e4h
Table index
1
The baud rate becomes active after saving the changes, and the next time the
encoder is switched on. To save the baud rate, the following command must be
sent:
Data source COB-ID
Controller 7e5h
Sensor 7e4h
6.3.8 Parameterizing CANopen®
6.3.9 CANopen® - system start
After configuring the node parameters, the device can be integrated into the net‐
work. When switched on or reset, the encoder performs a hardware initialization
to bring all components into a defined initial state. Next the device- and commu‐
nication-specific parameters are loaded from an EEPROM and the configuration
adopted.
Once the initialization has been completed, the device reports its node ID and
pre-operational status to the network master by means of a boot-up message.
While in this mode, the device can be configured via service data objects (SDOs).
The SDO identifiers are generated automatically based on the node ID. The com‐
munication via SDOs to configure the device takes the form of a peer-to-peer
connection between the network master and the device. The identifiers for the
other objects are also allocated according to the CANopen® standard. They can,
Data Destination
04; 01; 00; 00; 00; 00; Sensor
00; 00
11; 7d ; 00; 00; 00; 00; Sensor
1
00; 00
11; 00; 00; 00; 00; 00; Controller
00; 00
Data
17
17; 00; 00; 00; 00; 00; 00; 00 Controller
Baud rate (kBit/s) Table index
1000 00
800 01
500 02
250 03
125 04
50 06
20 07
10 08
Data
04; 01; 00; 00; 00; 00; 00; 00 Sensor
13; 00; 02 ; 00; 00; 00; 00;
1
00
13; 00; 00; 00; 00; 00; 00; 00 Controller
Data
17; 00; 00; 00; 00; 00; 00; 00 Sensor
17; 00; 00; 00; 00; 00; 00; 00 Controller
Destination
Sensor
Destination
Sensor
Destination
DAX® | SICK 14