TOPIC: Regdarding of tags.

Dear Sir,

Accroding to me Hoilding Coils for digital input, Discrete Input for DIgital output,Hoilding Registers for Analog input and Input Regsister.

How is the Point type used? Please explain the PLC and SCADA side tags.

Best Regards,
Chetan Kashyap

Dear Chetan,

I don't understand your question. According to Modbus protocol specification there are 4 register fields: Holding Coils (you can write and read boolean values there), Discrete Inputs (you can only read boolean values), Holding Registers (16 bits register to write and read) and Input register(16 bits registers for read). For every field in Modbus protocol used specific function commands.

Best regards,
Ruslan

It is clear now.

How can use of data type for holding Registers and input registers ?

Best Regards,
Chetan

It is clear now.

How can use of data type for holding Registers and input registers ?

Best Regards,
Chetan

You can use and data type for Holding Registers and Input Register. For Boolean data type you should choose bit that you bind to this tag. For some data type you use several registers. For example Float data type use 2 registers.

Best regards,
Ruslan