I use "ModBus simulator" that work very well!
But I have this problem:
• LAN with:
o Router/Switch with ADSL IP fixed public (220.127.116.11 – Sample Only)
o PC1 with IP 192.168.1.2
o PC2 with IP 192.168.1.2
o PC With ModBus Simulator (Slave) with IP 192.168.1.200
• When I use “ModScan32” (or other software Master) installed in PC1 or PC2 reading data from PLC 192.168.1.200 all works fine!!!
• After that I have “opened” the TCP port 502 on Router routing that on Local IP 192.168.1.200
• But if I try to access data passing through internet (simply changing IP in “Connect” of "ModScan32" writing that associated to ADSL connection) the connection don’t go!
• The port 502 is correctly open (I try this using a “PFPortChecker” utility)
• My Router is Dlink DSL-G604T
• Any idea?
Thanks for all and Good Christmas