Omron CQM1-ARM21, Руководство по эксплуатации

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