Transfer Time In Transfer Sequence - Mitsubishi Electric FX3U-232-BD User Manual

FX Series PLC User's Manual - Data Communication Edition
Computer Link
6.5.3

Transfer time in transfer sequence

This subsection explains how to calculate the approximate time after the computer starts data transfer and
the PLC gives a response until all communication is completed.
For the contents of T0 to T5, refer to the previous page.
1. When the computer reads data from the PLC
Communication time = T0 + (T1 + Longer time between T2 and TW) + T3 + T4 + T5
T0, T3, T5 =
T1: Maximum one scan time (Because data is read from the PLC during the END processing while the
PLC is in RUN mode, reading requires up to one scan time depending on the sending timing.
Reading requires about 1 ms while the PLC is in STOP mode.)
T2: END processing time in the PLC executing data transfer
T4: Scan time or longer (In the case of wiring in the 1-to-N configuration, T4 should be longer than the
time-out time setting (D8129) extended by one scan time.)
TW: Message waiting time
2. When the computer writes data to the PLC
Communication time = T0 + (T1 + Longer time between T2 and TW) + T3
T0, T3 =
Baud rate
 Number of characters
T1: Maximum one scan time (Because data is written to the PLC during the END processing while the
PLC is in RUN mode, writing requires up to one scan time depending on the sending timing. Writing
requires about 1 ms while the PLC is in STOP mode.)
T2: END processing time in the PLC executing data transfer
TW: Message waiting time
1
 Number of bits in one character (1 + 7 (8) + 0 (1) + 1 (2))
Baud rate
 Number of characters
1
 Number of bits in one character (1 + 7 (8) + 0 (1) + 1 (2))
6 Control Procedures and Setting Methods
6.5 Transfer Sequence Time Chart and Communication Time
Start Data length
(7 or 8)
bit
Start Data length Parity bit
(7 or 8) (0 or 1)
bit
Parity bit Stop bit
(0 or 1) (1 or 2)
Stop bit
(1 or 2)
D-55
A
B
C
D
E
F
G
H
I
Apx.A