8800 Process Controller As Modbus Master - WEST 8800 Operating Manual

7.4 8800 process controller as Modbus master

a
This function is only selectable with 8800/8840 configurator (engineering tool)!
Additions othr
Name
MASt
Cycl
AdrO
AdrU
Numb
The 8800 process controller can be used as Modbus master ( ConF / othr /
MASt = 1 ). The Modbus master sends ist data to all slaves (Broadcast message,
controller adress 0). It transmits its data (modbus adress AdrU) cyclic with the
cycle time Cycl to the bus. The slave controller receives the data transmitted by
the masters and allocates it to the modbus target adress AdrO. If more than one
data should be transmitted by the master controller ( Numb > 1) , the modbus
adress AdrU indicates the start adress of the data that should be transmitted and
AdrO indicates the first target adress where the received data should be stored.
The following data will be stored at the logically following modbus target
adresses.
With this it is possible e.g. to specify the process value of the master controller as
set-point for the slave controllers.
8800 process controller
(only visible with 8800/8840 configurator!)
Value range Description
Controller is used as Modbus master
0 Slave
1 Master
0...200 Cycle time [ms] for the Modbus master to transmit its data
to the bus.
1...65535
Target address to which the with
given out on the bus.
1...65535 Modbus address of the data that Modbus master gives to
the bus.
0...100 Number of data that should be transmitted by the Modbus
master.
73 8800 process controller as Modbus master
Special functions
AdrU
specified data is
Default
0
60
1
1
0