Chapter 8 Modbus Communication
8-5
Set the contents as follows.
Item
Setting
C
ontents
Station No.
Set a number between 0 to 31 (Don’t assign no. 0 as broadcasting station
lest it may be a cause for mistaken operation)
Baud Rate
Set one from 1200, 2400, 4800, 9600, 19200, 38400, or 57600 bps.
Data Bit
Set 7 or 8.
ASCII mode: Set as 7 bits.
RTU mode: Set as 8 bits.
Parity Bit
Set as one of None, Even, or Odd.
Stop Bit
Set 1 or 2 bit(s).
When parity bit is set: Set as 1 bit.
When parity bit isn’t set: Set as 2 bits.
Time out in
Master Mode
•
It’s the time waiting a responding frame since the master MK80S main
unit sends a request frame.
•
The default value is 500ms.
•
It must be set in consideration of the max. periodical time for
sending/receiving of the master PLC.
•
If it’s set smaller than the max. send/receive periodical time, it may
cause communication error.
Modbus
Master/ Slave
If it is set as the master, it’s the subject in the communication system. If
it’s set as the slave, it only responds to the request frame of the master.
Transmission
Mode
Select ASCII mode or RTU mode.