Mitsubishi FX3U Series User Manual page 19

FX Series Programmable Controllers
3U
User's Manual - MODBUS Serial Communication Edition
Example Link Time Calculations:
Master processing time (Tm)
D8411
Max Scan Time
Command
Frame Mode
Bytes in Request
Bytes in Response = 25bytes (1byte Address Echo, 22byte Frame, 2byte CRC)
Character Length
Baud Rate
Slave Delay
T4 = 5ms
T1 = INT
T6 ≈ 1ms
8 Bytes
T7 =
T8 = 10ms
25
T9 =
3.5
T10 =
T5 = 1ms + 5.2ms + 10ms + 14.0ms + 2.8ms = 33ms
T2 = INT
T3 ≈ 1ms
Tm = 5ms + 35ms + 1ms = 41ms
Slave processing time (Ts)
Command
Frame Mode
Bytes in Request
Bytes in Response = 25bytes (1byte Address Echo, 22byte Frame, 2byte CRC)
Character Length
Baud Rate
D8411
Max Scan Time
8
T14 =
T15 = 5ms
T11 = 5.2ms + 5ms + 5ms = 15.2ms
T12 ≈ 1ms
25 Bytes
T13 =
Ts = 15.2ms + 1ms + 14.0ms = 30.2ms
= 5ms
= 5ms
= Read Holding Registers 0-9 (Command Code 0x03)
= RTU Mode
= 8bytes (1byte Address, 5byte Frame, 2byte CRC)
= 10bits (1bit Start, 8bit Data Length, 0bit Parity, 1bit Stop)
= 19.2Kbps
= 10ms
5ms
(
+ 1 * 5ms = 1 +
5ms
in Request * 10bits
19200bps
Bytes in Response * 10bits
19200bps
Characters * 10bits
*
19200bps
33ms
(
5ms
+ 1 * = 6 +
5ms
= Read Holding Registers 0-9 (Command Code 0x03)
= RTU Mode
= 8bytes (1byte Address, 5byte Frame, 2byte CRC)
= 10bits (1bit Start, 8bit Data Length, 0bit Parity, 1bit Stop)
= 19.2Kbps
= 5ms
= 5ms
Bytes in Request * 10bits
19200bps
in Response * 10bits
19200bps
)
1 5ms = 10ms
*
≈
1000 (ms) 1ms 5.2ms
* +
≈
1000 (ms) 1ms 14.0ms
* +
≈
1000 (ms) 1ms 2.8ms
+
)
1 * 5ms = 35ms
1000 (ms) ≈
* + 1ms 5.2ms
≈
1000 (ms)
* + 1ms 14.0ms
2 Specifications
2.2 Link Time
1
2
3
4
5
6
7
8
9
10
15