Omron SMARTSLICE - 04-2008 Operation Manual page 82

Remote I/O Communications Characteristics
Note
Maximum I/O
Response Time
DeviceNet
Communications Unit
Slice bus
Input Unit
Output Unit
Note
DeviceNet
Communications
Cycle Time (T )
RM
T : The Input Slave's communications time/Slave
RT-IN
T : The Output Slave's communications time/Slave
RT-OUT
T : The DeviceNet communications time/Slave
RT
T : The PLC's cycle time
PLC
T : The PLC's DeviceNet Unit refresh time
RF
Refer to the GRT1 Series Slice I/O Units Operation Manual for details on Input
Unit's input delay times and Output Unit's output delay times.
The maximum I/O response time (T
T = T + 2×T
MIN IN
PLC
T
T
SL- CI
T
SL
T
IN
T : The Input Unit's ON (OFF) delay
IN
T : The Output Unit's ON (OFF) delay
OUT
T : The Slice bus communications cycle time
SL
T : The Slice Communications Unit's input data processing time
SL-CI
T : The Slice Communications Unit's output data processing time
SL-CO
T : The entire DeviceNet communications cycle
RM
T : The PLC's cycle time
PLC
T : The PLC's DeviceNet Unit refresh time
RF
Refer to the GRT1 Series Slice I/O Units Operation Manual for details on Input
Unit's input delay times and Output Unit's output delay times
The DeviceNet communications cycle time is the time from the completion of
a Slave's remote I/O communications processing until remote I/O communica-
tions with the same Slave are processed again. The communications cycle
time is used to calculate the maximum I/O response time.
The following equations show the communications cycle time (T
there is only one Master in the Network.
Even if the equation result is less than 2 ms, the minimum communications
cycle time (TRM) is 2 ms.
Σ
T = (communications time per Slave: T
RM
+ SmartSlice processing time
+ Explicit message communications time
+ COS/Cyclic connection communications time [ms]
+ 0.01 × N + 1.0 [ms]
) is the total of the following terms:
MAX
+ T + T + 2×T
SL SL-CI SL-CO
T T
PLC
T T
RF RF
RM
Section 5-1
+ 2×T + T
RM PLC RF
T
PLC PLC
T
RF
T
RM
T
SL-CO
)
RT
+ T
OUT
T
SL
T
OUT
) when
RM
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