Mitsubishi FX3U Series User Manual page 18

FX Series Programmable Controllers
3U
User's Manual - MODBUS Serial Communication Edition
The Master processing time (Tm) can be calculated in milliseconds (ms) as follows, where INT (n) indicates
the concatenation of any remaining decimal values.
Character Length (bits):
Start bit (1bit) + Data Length (7bit or 8bit) + Parity (0bit or 1bit) + Stop bit (1bit or 2bit)
Tm = T1 + T2 + T3
T1 = INT
T4 = D8411 (or D8431, depending on the Communication Channel)
T2 = INT
T5 = T6 + T7 + T8 + T9 + T10
T6 = less than 1ms
Number
T7 =
T8 = Slave Delay Time (depending on the Slave)
Number
T9 =
RTU Mode:
T10
ASCII Mode:
T10 = 0
T3 = less than 1ms
The Slave processing time (Ts) can be calculated in milliseconds (ms) as follows.
Character Length (bits):
Start bit (1bit) + Data Length (7bit or 8bit) + Parity (0bit or 1bit) + Stop bit (1bit or 2bit)
Ts = T11 + T12 + T13
T11 = T14 + T15 + Max Scan Time
T14 =
T15 = D8411 (or D8431, depending on the Communication Channel)
T12 = less than 1ms
Number
T13 =
14
T4
+ 1
Max Scan Time
T5
+ 1
Max Scan Time
of Bytes in Request
Baud
of Bytes in Response
Baud
3.5 Characters * Character
=
Baud Rate
Number of Bytes in Request
Baud
of Bytes in Response
Baud
* Max Scan Time
* Max Scan Time
* Character Length
Rate (bps)
* Character Length
Rate (bps)
Length (bits)
1000 (ms)
*
(bps)
* Character Length
Rate (bps)
* Character Length
Rate (bps)
(bits)
1000 (ms) 1ms
* +
(bits)
1000 (ms)
1ms
* +
1ms
+
(bits)
1000 (ms) 1ms
* +
(bits)
1000 (ms) 1ms
* +
2 Specifications
2.2 Link Time