User`s manual

14
FX3U Series Programmable Controllers
User’s Manual - MODBUS Serial Communication Edition
2 Specifications
2.2 Link Time
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
T4 = D8411 (or D8431, depending on the Communication Channel)
T5 = T6 + T7 + T8 + T9 + T10
T6 = less than 1ms
T8 = Slave Delay Time (depending on the Slave)
RTU Mode:
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
T15 = D8411 (or D8431, depending on the Communication Channel)
T12 = less than 1ms
TimeScanMax*1
TimeScanMax
T4
INTT1 +=
TimeScanMax*1
TimeScanMax
T5
INTT2 +=
1ms1000 (ms)
*
(bps)RateBaud
(bits)LengthCharacter*RequestinBytesofNumber
T7 +=
1ms
*
(bps)RateBaud
(bits)LengthCharacter*ResponseinBytesofNumber
T9 +=
1000 (ms)
1ms
*
(bps)RateBaud
(bits)LengthCharacter*Characters3.5
T10 +=
1000 (ms)
1ms
*
(bps)RateBaud
(bits)LengthCharacter*RequestinBytesofNumber
T14 +=
1000 (ms)
1ms
*
(bps)RateBaud
(bits)LengthCharacter*ResponseinBytesofNumber
T13 +=
1000 (ms)