Omron C200HW-CORT21, Operation Manual

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Performance
Section 1-3
21
t
RF
: The I/O Refresh time
t
PE
: The Program Execution time
First, an IOWR must be executed to indicate to the Unit which identifier(s) to
receive and to which PLC memory locations the received message(s) must
be transferred. This only needs to be done once and only needs to be
repeated when a different identifier needs to be received or when the
received message(s) need to be transferred to another PLC memory area.
After the IOWR instruction, the Unit is ready to receive messages. The
C200HW-CORT21 is able to store 15 messages and the buffer is transferred
to the PLC during the I/O refresh.
The minimum PLC cycle time (
t
PE
+
t
RF
) with one message received (and
transferred to the PLC) is 2.1 ms. This means that about 450 messages can
be received per second.
The maximum receive message rate of C200HW-CORT21 is achieved when
more messages are received per PLC cycle, e.g. PLC cycle time is 7.5 ms
and during this time 15 messages are received.