RS485

[MTZOVARAS]

Hi,

i have one COM port in RS485 mode with 2 devices on this port.
One is MODBUS with ID6 so the dataprocessor of the port is nrModbus1
For the other device with ID1 i have a different nrDataProcessor

How to manage the two different dataprocessors ?


Thank you,

[Roman Novgorodov]

Hello

You need to use ONE instance of nrModbus component. It allows to change ADDRESS for request different modbus slaves. You can read various modbus slaves, see following code:

Code Select Expand


nrModbus1.WriteRegister($1234, 11, 6);  // write value 11 into REGISTER 0x1234 for modbus slave  6
nrModbus1.WriteRegister($1234, 11, 7);  // write value 11 into REGISTER 0x1234 for modbus slave  7



Roman Novgorodov

[MTZOVARAS]

Sorry for the misunderstanding !
It was my fault !

The second device is not modbus.
It is a device where i send an ASCII command and replies with ASCII line.
I have a nrDataProcessor for the second device and an nrModbus for the first.

Do i have to activate once the nrModbus and once the nrDataProcessor and vice versa
or
is there a way to have the two of them activated  ?

[Roman Novgorodov]

Hello

It is not good idea to use one serial line with two devices with two different data transfer protocols.
Of course, You can try to use something like following:

Code Select Expand


nrComm1.DataProcessor := nrDataProcessor1;
nrDataProcessor1.DataProcessor := nrModbus1;


But there are no guaranties to correct work, it depends on data transfer logic.

Instead that you can switch between necessary protocols at runtime:

Code Select Expand


// switch to custom ASCII protocol
nrModbus1.Active := false;
nrComm1.DataProcessor := nrDataProcessor1;
nrDataProcessor1.Active : = true;

// switch back to modbus
nrDataProcessor1.Active : = false;
nrComm1.DataProcessor := nrModbus1;
nrModbus1.Active := true;


Roman Novgorodov
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