Omron DRT1 Series - Remote I;O Communications Characteristics; I;O Response Time

300
Remote I/O Communications Characteristics Section 7-1
7-1 Remote I/O Communications Characteristics
This section describes the characteristics of DeviceNet communications when
OMRON Master and Slave Units are being used. Use this section for refer-
ence when planning operations that require precise I/O timing.
The equations provided here are valid under the following conditions:
1,2,3... 1. The Master Unit is operating with the scan list enabled.
2. All of the required Slaves are participating in communications.
3. No errors are being indicated at the Master Unit.
4. Messages are not being produced in the Network (from another company’s
configurator, for example).
Note The values provided by these equations may not be accurate if another com-
pany’s Master or Slave is being used in the Network.
7-1-1 I/O Response Time
The I/O response time is the time it takes from the reception of an input signal
at an Input Slave to the output of the corresponding output signal at an Output
Slave.
CV-series PLCs
(Asynchronous Mode)
The following timing charts show the minimum and maximum I/O response
times of the DeviceNet Network for a CV-series PLC operating in asynchro-
nous mode.
Minimum I/O Response Time
The minimum I/O response time occurs when the DeviceNet Master Unit
refreshing is executed just after the input signal is received by the Master and
instruction execution is completed within one peripheral servicing cycle.
T
IN
: The Input Slave’s ON (OFF) delay (Minimum value: 0.)
T
OUT
: The Output Slave’s ON (OFF) delay (Minimum value: 0.)
T
RT-IN
: Input Slave’s communications time/Slave (See page 306.)
PLC cycle
(instruction execution cycle)
Master Unit processing
Input
Output
PLC cycle
(peripheral servicing cycle)
Instruction
execution
Instruction execution
cycle time
Peripheral
servicing cycle
time
TPLC2