Longo programmable controller LPC-2.MC8
CANopen unit
CANopen unit consists of Master and Slave communication ports. They are independent, thus can be
connected to two different CAN networks at the same time.
The ports can operate at baud rates 50 kbps, 125 kbps or 250 kbps.
It follows the internationally standardized (EN 50325-4) CAN-based higher-layer protocol for
embedded control systems. Advised rules and concepts by this standard must be followed to fulfill
the conditions and so achieving normal operation and results.
The structure of the network as cable type and lengths, baud rates, number of the nodes and
termination must be taken into account within the recommendations and requirements, when
designing the network.
The bus network can consist of at least one Master and at list one Slave node by the standard, but it
is advised that with increased number of nodes, the Master node fastest interval is extended. Below
are two examples:
Example1
: network with 1 master and 9 slaves, every slave have defined 32 (4x8) byte of data and
baud rate 125 Kbps. Fastest Cycle time for this configuration is 50 ms.
Example2
: network with 1 master and 4 slaves, every slave have defined 4 byte of data and baud
rate 250 Kbps. Fastest Cycle time for this configuration is 5 ms.
5 millisecond is the fastest recommended cycle time.
It is recommended to power-up all the nodes on the same network at the same time, if some or all
nodes had been reprogrammed (to reinitialize the communication properly).
Additional operational information
After the installation of the PLC it must be at least 20 minute enabled power supply, before the
internal battery is charged and the retain memory is ready to save variables without loosing them
switching power supply off.
RUN / STOP Switch
Run mode: Status (RUN) LED on indicate that the PLC program is up and user program is running.
Stop mode: When the switch is turn to STOP state, the status (RUN) LED is Off. The application
switch to the bootloader, this fact allow users to program LPC-2.MC8.
When the user is done programming the PLC via USB the switch must be turned ON and the MC8
starts the application.
PLC task cycle time
Main PLC task interval (under Project tab -> Resource Tasks Interval) time is not recommended
→
→
to be set lower than 50 ms.
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