Omron CJ1W-DRM21 Operation Manual page 224

8 Communications Timing
N is the smallest value that meets the following condition.
RMMAX
× T
N > T
RMMAX RM
T = T
RFNJ INNJMAX
y = ((Number of CPU Bus Units + 1) × 1 ms) ÷ Task period
Note Truncate the decimal portion of y and use the resulting integer in the formula.
T : Input processing time in CPU Unit (ms)
INNJMAX
T : Output processing time in CPU Unit (ms)
OUTNJMAX
Task period: The period of the task in which I/O refreshing is assigned for the DeviceNet Unit (ms)
Number of CPU Bus Units: The number of CPU Bus Units that are connected in the Controller
= 0.5 + 0.0005 × Total size of all master input data in bytes
T
INNJMAX
= 0.2 + 0.0006 × Total size of all master output data in bytes
T
OUTNJMAX
However, if the DeviceNet Unit is on an Expansion Rack, use the following formulas to calculate T
and T
MAX OUTNJMAX
= 0.5 + 0.00075 × Total size of all master input data in bytes
T
INNJMAX
= 0.2 + 0.0009 × Total size of all master output data in bytes
T
OUTNJMAX
Formula for the Minimum I/O Response Time
You can calculate the minimum I/O response time T
T = T + T
MIN IN RT-IN
T : Input slave ON or OFF delay (ms)
IN
T : Communications time per slave for input slaves (ms)
RT-IN
T : Communications time per slave for output slaves (ms)
RT-OUT
T : Output slave ON or OFF delay (ms)
OUT
T = T
RFNJ INNJMIN
T : Input processing time in CPU Unit (ms)
INNJMIN
T : Output processing time in CPU Unit (ms)
OUTNJMIN
Task period: The period of the task in which I/O refreshing is assigned for the DeviceNet Unit (ms)
= 0.4 + 0.0004 × Data size per slave for input slaves in bytes
T
INNJMIN
= 0.1 + 0.0005 × Data size per slave for output slaves in bytes
T
OUTNJMIN
However, if the DeviceNet Unit is on an Expansion Rack, use the following formulas to calculate T
and T
NJMIN OUTNJMIN
= 0.4 + 0.0006 × Data size per slave for input slaves in bytes
T
INNJMIN
= 0.1 + 0.00075 × Data size per slave for output slaves in bytes
T
OUTNJMIN
8-6
RFNJ
+ Task period × (3 + y) + T
.
+ T + T + T
RT-OUT RFNJ OUT
+ Task period + T
OUTNJMIN
.
CJ-series DeviceNet Units Operation Manual for NJ-series CPU Unit(W497)
OUTNJMAX
(ms) with the following formula.
MIN
INNJ-
IN-