Mitsubishi Electric Melsec Q Series User Manual page 101

3
SPECIFICATIONS
(a) Bus cycle time (Bc) calculation formula
Bc[ms] Max (MSI,
Item
MSI[ms]
Minimum polling cycle (Min. slave interval)
(Polling time to i-th station) = Treq
Treq
•
= [{(Number of bytes output to i-th station) + 9} 11[bit]] 10
speed[bps])
Pt [ms]
(i)
Max_Tsdr(i)[ms] = (Response time [T
•
Tres
•
= [{(Number of bytes input from i-th station) + 9} 11[bit]] 10
speed[bps])
(Request/response processing time [T
Tsdi [ms]
(M)
(Transmission speed[bps])
Lr[ms]
(Data refresh time) = 5.50 + (Number of DP-Slaves)
The bus cycle time (Bc) of the DP-Master can be obtained from the following
calculation formula.
The symbols within the brackets [] indicate units.
n
(Pt
(i)
i 1
n=number of DP-Slaves
Max (A, B) = A or B, whichever is greater
Table3.23 Items in the bus cycle time (Bc) calculation formula
[ms] = (Request transmission time of i-th station)
(i)
[ms] = (Response transmission time of i-th station)
(i)
* 1 The value set on the Master Settings window of GX Configurator-DP
* 2 The MaxTsdr value described in the GSD (DDB) file of the DP-Slave
* 3 [T ] (Bit Time) is a unit that expresses the time required for 1-bit data transmission as "1".
Bit
The actual processing time differs as shown below depending on the transmission speed.
[Transmission speed is 1.5 Mbps]
6
1[T ]=1 / (1.5 10 )=0.667 10
Bit
[Transmission speed is 12 Mbps]
6
1[T ]=1 / (12 10 )=0.083 10
Bit
* 4 The Tsdi value described in the GSD (DDB) file of the QJ71PB92V
The Tsdi value varies as shown below depending on the transmission speed.
Refer to *3 for the unit [T ].
Bit
Table3.24 Request/Response Processing Time of DP-Master
Transmission speed
9.6kbps, 19.2kbps, 93.75kbps, 187.5kbps
500kbps
1.5Mbps
3Mbps
6Mbps
12Mbps
3.5 Processing Time
3.5.1 Bus cycle time
T sdi ) Lr)
(M)
Description
*1
+ Max_Tsdr + Tres
(i) (i) (i)
*2, *3
] of i-th station) 10
Bit
] of DP-Master(QJ71PB92V)
Bit
150
-6 -3
[s] = 0.667 10 [ms]
-6 -3
[s]= 0.083 10 [ms]
Request/Response Processing Time of DP-Master
3
/ (Transmission
3
/ (Transmission speed[bps])
3
/ (Transmission
*4 3
10 /
-3
10
70T
Bit
150T
Bit
200T
Bit
250T
Bit
450T
Bit
800T
Bit
3
- 60
1
2
3
4
5
6
7
8