Mitsubishi Electric Melsec QJ71LP21 Reference Manual page 89

3 SPECIFICATIONS
Receiving
station
Non-redundant
Sending
station
Non-redundant Expression of 1)
system
Redundant system Expression of 2)
(Note that the Ts
value is "0.")
3 - 35
REMARKS
When executing transient transmissions from multiple stations at the same time, the
execution time of the instruction may be shortened by increasing the setting value
for the maximum number of transient requests in one link scan.
For instance, when there are seven stations that execute an instruction, the time for
"LS 4" may be shortened by changing the setting value of the maximum transient
requests from the default value of two to seven or larger with the transient setting in
the supplementary settings of the common parameters of GX Developer.
Note, however, that the scan time of the CPU module increases by that time amount.
(c) READ, WRITE, REQ, RRUN, RSTOP, RTMRD, or RTMWR instruction
communication
The transmission delay time in communication with the READ, WRITE, REQ,
RRUN, RSTOP, RTMRD, or RTMWR instruction depends on the system of the
sending and receiving stations.
Access to control
system
system CPU
Expression of 2)
(Note that the Ts
value is "0.")
Expression of 2)
R
The transmission delay time in instruction communication can be calculated from
the following:
• Scan time of the sending and receiving stations (except link refresh time)
• Link refresh time
• Link scan time
• Scan time delay due to tracking transfer
[Transmission delay time in READ/WRITE/REQ/RRUN/RSTOP/
RTMRD/RTMWR instruction communication]
+ 
1) T = (S + S
D4 T T
(MAX : T = (S
D4 T
+ 
2) T = (S + Ts
D5 T T
(MAX : T = (S +
D5 T
+ 
3) T = (S + Ts
D6 T T
(MAX : T = (S +
D6 T
Redundant system
Host system
Access to standby
system CPU
Expression of 2)
(Note that the
T
values of Ts , S
T
and α are "0.")
R
Expression of 2)
(However, the
values of S , and
R
α are "0.")
R
+ 
) 2 + (LS 4) + LS
R R
+  + 
+ S ) 2 + (LS
T R R
+ 
+S +Ts ) 2 (LS
T R R R
+  Ts
+ Ts + S
T T R R
+ 
+S +Ts )
T R R R
+  Ts
+ Ts + S
T T R R
Other system
Access to standby
system CPU via
control system
Expression of 3)
(Note that the Ts
T
, value is "0.")
R
Expression of 3)
[ms]
U
6) + LS )
U
4) + LS [ms]
U
) 2 + (LS 6) + LS
R
2 (LS 4) + 3 + LS [ms]
U
) 2 (LS 6) + 6 + LS
R
MELSEC-Q
Access to control
system CPU via
standby system
Expression of 3)
(Note that the
values of Ts , S ,
T R
and α are "0.")
R
Expression of 3)
(Note that the
values of S , and
R
α are "0.")
R
)
U
)
U
(To next page)
3 - 35