SIMATIC S7-300, CP 340 Communications processor with 20 mA interface (TTY), E-Stand: 02. SIMATIC S7-300 CP 340 Communications processor with 20 mA interface (TTY) E-Stand: 02 6ES7340-1BH02-0AE0 Siemens is a high-quality programmable logic controller (PLC) module suitable for industrial automation applications. This item can be purchased at PLC2Day.