Home PLC using PIC microcontroller

[RITESH]

Hi,

I need guidance for programming pic uC as PLC for communicating with SCADA, in touch for visualization of little discrete process on screen.
I have read about modbus, but need help for writing code.

thanks

[temtronic]

Well that's a wide open question !!
Programming a PIC as a PLC is easy ONCE you've defined all the parameters.
number of inputs?
type of inputs?
number of outputs?
type of outputs?
logic required?
timers?
conditionals?
and that's only the begining...
Once built a 'PLC' using a 12F683 to control a stairwell lighting system(3 inputs, 1 output)..so really you need to tell us more.


SCADA(Supervisory Control And Data Acquistion) is a fancy name that is everything to everybody but means nothing without the details.

Not all 'PLC's use MODBUS, it's just one companies idea of a 'programming system'.

[Gabriel]

i would think that by using the term PLC he is referring to a very robust and protected industrial type of device...as opposed to a simple logic controller board or bread board experiment...

so, you need to define how will you protect your supply, your inputs, your outputs, and WHAT are your outputs/inputs...as in: optocoupled digital inputs, analog inputs? dry contacts? coils?
_________________
CCS PCM 5.078 & CCS PCH 5.093

[RITESH]

Hi,

I am using Wonder ware in touch SCADA.
I need to start home made PLC just from,
few inputs and outputs no analog & timer just for now, digital output connected to in touch ascii .

[FvM]

The CCS C modbus example (ex_modbus_slave.c) can be a starting point for the communication part.

[RITESH]

Where to find it?

[Sergeant82d]

Umm... In the "examples" folder would be a great place to start looking...