Mitsubishi Electric Melsec Q Series User Manual page 108

3
SPECIFICATIONS
Bus terminator
Trc
Tsw[ms]
(
3
- 67 3.5 Processing Time
3.5.3 System switching time in redundant system
(b) Redundant system switching time calculation example
Shown below is a calculation example for the system switching time in the
redundant system.
The calculation is based on the following conditions:
• Scan time is 5 [ms].
• AND is set in System switching condition (Un\G23648)
• In System switching DP-Slave specification (Un\G23649 to Un\G23656), 1st
to 3rd DP-Slaves are set as switching targets.
DP-Master (FDL address 0)
QJ71PB92V
DP-Slave (FDL address 2)
AJ95TB2-16T
Input : 0 points
Output: 16 points
Output data size [byte]
Input data size [byte]
Figure 3.42 System Configuration Example
1) TcpuA [ms] value
TcpuA [ms] = 5 + 3 = 8 [ms]
2) Tsw [ms] value
Item
The following is calculated based on the case where signal flow memory is not
1
tracked.
[ms]
The following is calculated based on the case where redundant CPUs are used and
the number of words to be auto-refreshed is 5.
T m = 27[ s] + 6[ s]
2
T m
[ms]
The following conditions are applied.
• Signal flow memory is not tracked.
• No SFC program is executed.
• No PID control instructions (PIDINIT, S.PIDINIT) are executed.
• Tracking devices are D0 to D31 (32 points).
3
• Number of tracking blocks is 1.
[ms]
)
• One tracking device range setting
Trc = 1 + (32
Tsw = 20.5 + 0.057 + 1.01 = 21.567 [ms]
+ + )
1 2 3
DP-Master (FDL address 1)
QJ71PB92V
DP-Slave (FDL address 3)
AJ95TB3-16D
Input : 16 points
Output: 0 points
AJ95TB2-16T AJ95TB3-16D QJ71PB93D
2 0
0 2
Table3.32 Tsw [ms] value
= 20.5 [ms]
Number of words to be auto-refreshed
=27[ s] + 6[ s] 5[word]
=57[ s]
=0.057[ms]
-3
0.09 10 ) + (1
= 1.00788 = 1.01[ms]
Transmission speed : 1.5Mbps
No. of DP-Slave
Bus terminator
PROFIBUS-DP
DP-Slave (FDL address 4)
QJ71PB93D
Input : 1 word
Output: 2 words
4
2
-3 -3
4 10 ) + (1 1 10 )
: 3 modules