Omron CQM1-ARM21 Operation Manual page 36

Performance
Maximum I/O response time
22
The figure below illustrates the maximum I/O response time. Shown are the
timing at the PLC CPU, the timing at the Master Unit, the timing at the slave
input and the timing at the slave output.
CPU
Master
Bus
t
BC1
Input t
IN
Output
t : Input Slave's ON (OFF) delay.
IN
Physical signal change at the terminals → data available for trans-
mission.
t : Bus cycle time.
BC1
If the slave's input data has changed just after a data exchange on
the bus, it will take one AS-Interface bus cycle before the slave gets
serviced again.
t : Master processing time.
MP1
Start receiving slave response → data available at the I/O bus.
t : I/O refresh time.
RF
Time required to update inputs and outputs of all CQM1 I/O units.
t : Program Execution time
PE
Processing of the PLC program and peripherals
t : PLC Cycle time (scan time) = t
PLC
t : Master processing time.
MP2
Data available at the I/O bus interface → ODI updated.
t : Bus cycle time.
BC2
If the ODI update took place just after the output slave has been
serviced by the master, it will take one full AS-Interface bus cycle
before the same slave gets serviced again.
t : Output Slave's ON (OFF) delay.
OUT
Data received from master → physical signal change at the termi-
nals.
t = t + (2*t ) + (2*t
RESPONSE IN BCx
in which t and t
IN
using a programming console or by monitoring AR27 in the CPU.
The maximum value of T
The value of T
mal circumstances has a maximum of 5.0 ms at 31 slaves.
t
PLC
t t t t
RF PE RF PE
t
MP1
t
RESPONSE
+ t
PE RF
) + (2*t ) + t
MPx PLC OUT
are slave dependent, and t
OUT
is 2.0 ms.
MPx
depends on the number of slaves, and under nor-
BCx
Section 3-3
t
RF
t
MP2
t
BC2
t
OUT
can be determined
PLC