Reply Times For Modbus Communication - ABB AC 31 Technical Manual

1.4. Reply times for MODBUS communication

Page 7-10
Communication
The MODBUS processing time depends on:
- The transmission speed
- The number of frame bytes
- The central unit cycle time
- The central unit load factor
The following times are for indication purposes only.
Reply times with a 40 or 50 series central unit
G G G G
Cycle time = 10 ms
Load factor = 80%
Speed = 9 600 Bauds
Nr. of variables
1
10
50
100
150
255
Bits
read (ms) write (ms)
10 - 60 50
10 - 60 60
10 - 60 110
50 - 60 110
50 - 110
50 - 110
Words
read (ms) write (ms)
10 - 60 60
10 - 60 110
110 - 170 220
220 -280 390
- -
- -
ABB Control - AC 31
1SBC 260400 R1001-b 06.99