Omron DEVICENET#05-2003 Operation Manual page 201

Remote I/O Communications Characteristics
Communications Time per
Slave
192
• For details about the communications time required for 1 Slave refer to
page 192. For the MULTIPLE I/O TERMINAL, it equals the communica-
tions time required for 1 Slave Unit of the Communications Unit.
munications time per Slave) is the total of the communications times for all
the Slaves in the network.
• Multiple Units processing time = 3.5 (ms). It is to be added only if there is
a Slave where the input or output exceeds 8 bytes.
• Explicit message processing time = 0.11
only when explicit message communications are executed. T
value (At 500 kbps = 2, 125 kbps = 4, 125 kbps = 8).
• N = Number of Slaves
The communications time per Slave is the communications time required for a
single Slave. The formula for calculating the communications time per Slave
(T ) for different types of Slave is shown below. For the MULTIPLE I/O TER-
RT
MINAL, it will be the communications time per Slave of the Communications
Unit. With the MULTIPLE I/O TERMINAL, 2 input words (4 bytes) are used for
notifying the status of I/O Unit interfaces. This must be included as the num-
ber of bytes when making calculations.
Output Slave with 8 Bytes of Output or Less
T = 0.016 T S
RT B OUT1
S : Number of output words for the Output Slave
OUT1
T : At 500 kbps = 2, 250 kbps = 4, 125 kbps = 8
B
Input Slave with 8 Bytes of Input or Less
T = 0.016 T S
RT B IN1
S : Number of input words for the Input Slave
IN1
T : At 500 kbps = 2, 250 kbps = 4, 125 kbps = 8
B
Mixed I/O Slave with 8 Bytes of Both Input and Output or Less
T = 0.016 T (S
RT B
S : Number of output words for the Mixed I/O Slave
OUT2
S : Number of input words for the Mixed I/O Slave
IN2
T : At 500 kbps = 2, 250 kbps = 4, 125 kbps = 8
B
Slave with more than 8 Bytes of Input or Output (or Both)
T = T + T
RT OH BYTE-IN
T : Protocol overhead
OH
T : Input byte transmission time
BYTE-IN
B : Number of input bytes
IN
T : Output byte transmission time
BYTE-OUT
B : Number of output bytes
OUT
Communication speed
500 kbps
250 kbps
125 kbps
If there are no Output Slaves, use 0 as the value of B
Slaves, use 0 as the value of B
+ 0.11 T + 0.07 (ms)
B
+ 0.06 T + 0.05 (ms)
B
+ S ) + 0.11
OUT2 IN2
B + T B
IN BYTE-OUT
T
CH
0.306 ms 0.040 ms
0.542 ms 0.073 ms
1.014 ms 0.139 ms
.
IN
Section 6-1
T + 0.6 (ms). It is to be added
B
T + 0.07 (ms)
B
(ms)
OUT
T T
BYTE-IN BYTE-OUT
0.036 ms
0.069 ms
0.135 ms
. If there are no input
OUT
(com-
is a fixed
B