Omron C200HW-CORT21-V1, Operation Manual

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Performance
Section 2-3
28
The Input / Output Node ON (OFF) delay
Refer to the manual of the Input / Output Node to determine its ON / OFF
delay time.
The Message Delay time
The message delay time is described in section 2-3-2.
The Unit Processing time for Transmitted / Received messages
The Unit processing time for received messages depends on the number of
PDOs linked to C200HW-CORT21-V1 and the message rate of these PDOs.
If the message rate is higher than the unit is capable of processing (see
section 2-3-2), the messages will queue up causing a delay in processing.
When a receive queue overflow occurs, the Unit will notify the other nodes in
the network by transmitting an emergency message.
The Unit processing time of messages to be transmitted depends on the
number and type of input application objects mapped to PLC memory and to
PDOs, and the rate at which these application objects change state. If many
objects change state, the transmission of PDOs will queue up causing a
delay in transmission. If the rate at which the objects change state requires
an higher transmission rate than the Unit is capable of (see section 2-3-2), a
transmit queue overflow occurs. The Unit will notify the other nodes on the
network by transmitting an emergency message.
Transmit queue overflow errors can be solved by increasing the PLC cycle
time or by reducing the rate at which the data objects change.
In case of high bus loads (over 50%), additional delays can be caused by
high-priority (low identifier) messages which delay the transmission of lower
priority messages.
The Unit processing time of I/O messages also depends on the transmission
types of the receive and transmit PDOs. The fastest transfer of an application
object to the PLC or onto the network can be achieved when the
transmission type is set to asynchronous. The synchronous transmission
type requires the reception of a SYNC object before the actual message is
transmitted.
The I/O Refresh time
Refer to section 2-3-1 for the I/O refresh time of the C200HW-CORT21-V1.
The Program Execution time
The Program Execution time depends on the number and type of PLC
instructions in the ladder program. Refer to the PLC Operation Manual for the
execution times of the PLC instructions.