FX communication
Computer link 7
7-13
7
7.5.3 Communication Time
This is to explain the method of calculating the approximate time until all communication is over.
For the locations of T0 to T4, see the previous page.
1 ) When reading data from the programmable controller to the computer
Communication time = T0 + (T1 + T2 or TW, whichever is longer) + T3 + T4 + T5
2 ) When writing data from the computer to the programmable controller
Communication time = T0 + (T1 + T2 or TW, whichever is longer) + T3
T0, T3, T5 =1/baud rate
×
number of bits in 1 character (1 + 7(8) + 0(1) + 1(2))
×
number of characters
T1 =max. 1 scan time (during RUN, message processing is done at END processing, a
maximum delay of 1 scan could occur depending on message timing; during STOP,
T1 is 1 ms)
T2 =END process time of programmable controller during data communication
T4 =A delay of at least 2 scans is required. However, using one-pair wiring on the 1:N
system configuration, this time need to set “Time-out timer value (D8129) + 1 scan
time” or more.
TW = set time when message wait is set.
Stop bit (1 or 2)
Data length (7 or 8)
Parity bit (0 or 1)
Start bit
T0, T3 =1/baud rate
×
number of bits in 1 character (1 + 7(8) + 0(1) + 1(2))
×
number of characters
T1 =max. 1 scan time (during RUN, message processing is done at END processing, a
maximum delay of 1 scan could occur depending on message timing; during STOP,
T1 is 1 ms)
T2 =END process time of programmable controller during data communication
TW = set time when message wait is set.
Stop bit (1 or 2)
Data length (7 or 8)
Parity bit (0 or 1)
Start bit
To Next Page
Loading...
