Справочник Пользователя для Mitsubishi Electronics AJ65BT-D75P2-S3
3 - 33
MELSEC-A
3 SPECIFICATIONS AND FUNCTIONS
Transient transmission
(1) When master module is AJ61BT11, A1SJ61BT11, AJ61QBT11 or
A1SJ61QBT11
(a) Calculation
expression
Details
Calculation expression (Unit: ms)
Master module D75P2
(write)
(write)
{SM 2 + LS 6 (number of write points
*1
+ 16)/72
*2
LS +
bps constant} N
Master module D75P2
(read)
(read)
{SM 2 + LS 5 (number of read points
*1
+ 16)/16
*2
LS +
bps constant} N
*1: Set in word unit
*2: Rounded up to the one place
*2: Rounded up to the one place
SM : Scan time of master module sequence program
LS : Link scan time (refer to the Master Module User's Manual)
LS : Link scan time (refer to the Master Module User's Manual)
: Number of read points
1 to 120points 121 to 240points 241 to 360points 361 to 480points
LS LS 2 LS 3 LS 4
bps constant
156kbps 625kbps 2.5Mbps 5Mbps 10Mbps
LS LS 2 LS 4 LS 6 LS 7
N : Number of simultaneously executed commands
(b) Calculation
example
The following example calculates the transmission delay time taken when
"
"
Md.30
Machine feed value" (2 words) is read from the D75P2.
When SM is 20ms, transmission speed is 10Mbps, and only one D75P2 is
connected
LS: 1.8ms (for the calculation expression, refer to "(2) Calculation example in
Cyclic transmission")
connected
LS: 1.8ms (for the calculation expression, refer to "(2) Calculation example in
Cyclic transmission")
Transmission delay time = {SM 2 + LS 5 + LS + (2 +16)/16 LS + LS 7} 1
= {20 2 + 1.8 5 + 1.8 + (2 +16)/16 1.8 + 1.8 7} 1
= 40 + 9 + 1.8 + 3.6 + 12.6
= 67[ms]
= 40 + 9 + 1.8 + 3.6 + 12.6
= 67[ms]
Therefore, the read machine feed value is the data after 67ms.
However, when data is read from the buffer memory whose update timing is at
56.8ms intervals
However, when data is read from the buffer memory whose update timing is at
56.8ms intervals
*1
, data after a maximum of 67 + 56.8 = 123.8ms is read as
shown below depending on the read timing.
*1
Md.37
update timing is at 910ms intervals.
D75P2 update timing
56.8ms
56.8ms
56.8ms
56.8ms
Md. 30 Machine feed value
1)
Read
execution
Read
complete
67+1) (ms)