63
Remote I/O Communications Characteristics
Section 5-1
T
RT-IN
: The Input Slave's communications time/Slave
T
RT-OUT
: The Output Slave's communications time/Slave
T
RT
: The DeviceNet communications time/Slave
T
PLC
: The PLC's cycle time
T
RF
: The PLC's DeviceNet Unit refresh time
Note
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.
Maximum I/O
Response Time
The maximum I/O response time (T
MAX
) is the total of the following terms:
T
MIN
= T
IN
+ 2×T
SL
+ T
SL-CI
+ T
SL-CO
+ 2×T
RM
+ 2×T
PLC
+ T
RF
+ T
OUT
T
IN
: The Input Unit's ON (OFF) delay
T
OUT
: The Output Unit's ON (OFF) delay
T
SL
: The Slice bus communications cycle time
T
SL-CI
: The Slice Communications Unit’s input data processing time
T
SL-CO
: The Slice Communications Unit’s output data processing time
T
RM
: The entire DeviceNet communications cycle
T
PLC
: The PLC's cycle time
T
RF
: The PLC's DeviceNet Unit refresh time
Note
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
DeviceNet
Communications
Cycle Time (T
RM
)
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
RM
) when
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.
T
RM
=
Σ
(communications time per Slave: T
RT
)
+ SmartSlice processing time
+ Explicit message communications time
+ COS/Cyclic connection communications time [ms]
+ 0.01 × N + 1.0 [ms]
T
PLC
T
RF
T
PLC
T
RF
T
PLC
T
RF
T
RM
T
SL-
CI
T
SL
T
IN
T
RM
T
SL-CO
T
SL
T
OUT
PLC
DeviceNet
Communications Unit
Slice bus
Input Unit
Output Unit
Summary of Contents for SMARTSLICE - 04-2008
Page 1: ...DeviceNet Communications Unit Cat No W454 E1 03 SmartSlice GRT1 DRT OPERATION MANUAL ...
Page 2: ...SmartSlice GRT1 DRT DeviceNet Communications Unit Operation Manual Revised April 2008 ...
Page 3: ...iv ...
Page 5: ...vi ...
Page 13: ...xiv ...
Page 27: ...8 Basic Operating Procedure Section 1 5 ...
Page 57: ...38 Unit Functions Section 2 3 ...
Page 101: ...82 DeviceNet Explicit Messages Appendix A ...
Page 113: ...94 Standard Models Appendix C ...
Page 115: ...96 Power Consumption Tables Appendix D ...
Page 117: ...98 I O Current Consumption Appendix E ...
Page 119: ...100 Glossary ...