Siemens S7 224 PLC
I apologize for mis-typing the PLC model. It should have been identified as S7 224. I've owned the unit since at least 2003. The communication module is just as old. My CP 243-IT manual describes only SMTP, FTP, AND HTTP; not TCIP. TCIP had just become the new protocol when I purchased the PLC and Siemens said that they doubted they would reconfigure the 200 series to include TCIP. Before my internet provider changed over to TCIP, I was actually able to modify and visit the remote location that housed the PLC via internet. But then my internet provider switched over to TCIP and left me stranded. I became frustrated and set the plc aside for these many years and made other house improvements at the remote location, instead. Since the newer CP-243-1 IT now have the TCIP protocol, I'll pursue it. Thanks.