Omron 3G3MV-PDRT2, User Manual

Page: 286 / 363

Chapter 10
10-28
Appendices
Mixed I/O Slaves with 8 or Less Bytes of Both Input and Output
T
RT
= 0.016
×
T
B
×
(S
OUT2
+S
IN2
) + 0.11
×
T
B
+ 0.07 (ms)
S
OUT2
: The number of Mixed I/O Slave output words
S
IN2
: The number of Mixed I/O Slave input words
T
B
: The baud rate factor
(500 kbps: T
B
= 2; 250 kbps: T
B
= 4; 125 kbps: T
B
= 8)
Slaves with More than 8 Bytes of Input or Output (or Both)
T
RT
= T
OH
×
T
BYTE-IN
×
B
IN
×
T
BYTE-OUT
×
B
OUT
(ms)
T
OH
: Protocol overhead
T
BYTE-IN
: Input byte transmission time
B
IN
: Number of input bytes
T
BYTE-OUT
: Output byte transmission time
B
OUT
: Number of output bytes
Note Calculate with B
OUT
= 0 for Slaves with inputs only and B
IN
= 0 for Slaves with outputs only.
High-density Unit Processing Time
Add 3.5 ms if there is at least 1 Slave with more than 8 bytes of input or output (or both).
Explicit Message Processing Time
Add the following explicit message processing time when performing explicit message communica-
tions (sending or receiving).
Explicit message processing time = 0.11
×
T
B
×
n (ms)
n: The number of explicit messages that are sent or received within 1 cycle of the CPU Unit
T
B
: The baud rate factor
(500 kbps: T
B
= 2; 250 kbps: T
B
= 4; 125 kbps: T
B
= 8)
COS/Cyclic Connection Communications Time
Add the following COS/cyclic connection communications time.
COS/cyclic connection communications time = (0.05 + 0.008
×
S)
×
T
B
×
n (ms)
S: The total number of input and output bytes for COS/cycle connections
T
B
: The baud rate factor
(500 kbps: T
B
= 2; 250 kbps: T
B
= 4; 125 kbps: T
B
= 8)
n: The number of nodes for which COS/cyclic connections occur within 1 cycle of the CPU Unit
● More than One Master in Network
Calculate the communications cycle time according to the above equation for the Slaves of each
Master Unit. The communications cycle time for the entire network is the sum of communications
cycle times for each Master Unit.
Baud rate T
OH
T
BYTE-IN
T
BYTE-OUT
500 kbps 0.306 ms 0.040 ms 0.036 ms
250 kbps 0.542 ms 0.073 ms 0.069 ms
125 kbps 1.014 ms 0.139 ms 0.135 ms