Fatek PLC No response received from PLC in realterm

[arham1026]

hi, I am kinda new to plc.I am working on Fatek FBS-20mct ac plc.I am sending commands from realterm to PLC to start a stepper motor but thing is which ever command i send gets echoed back on the realterm window.the rx line on my plc blinks when it receives data but tx line never blinks suggesting plc is not responding.I am usinf Port0 The Standard interface of PLC for this communication.What could be the reasons of PLC not responding?

[Mark-]

11 minutes ago, arham1026 said:

What could be the reasons of PLC not responding?

Many, wrong communication parameters, (baud rate, data bit count, etc.), malformed message, incorrect cable wiring, address does not exist, etc.

[IvanBratanov]

On 6/2/2025 at 3:29 PM, arham1026 said:

hi, I am kinda new to plc.

Being new to PLC requires smaller and simpler steps at the very beginning. Using serial or Ethernet connections via software and driving stepper motors are too complex endeavors for a newbie.
 

Jumping directly to complex things leaving empty early steps is an example of incorrect acquisition of knowledge because everything you skipped has its own important place.

Perhaps you should begin with PLC’s basic concepts (bits, nibbles, bytes, words etc), number systems, types of variables, registers and relays, ladder logic basic programming concepts, program scan methods.
 

Only then you may start writing simple programs with the PLC only (basic instructions, counters, timers, loop instructions, data transmission and comparison, arithmetic, data processing, high speed in/out).
 

Further when become more skilled you may start experiment with pulse train instructions.

 

And only then is time for more complex things like communications and networking.

Edited June 8 by IvanBratanov