PCD3 processor unit with Ethernet TCP/IP,
web and FTP server, file system,
CPU with 1 MByte user program,
backup option with PCD7.R5xx/R610 Flash card,
clock (RTC), data protection 1-3 years,
USB port for PG5, up to 1024 I/O, 2 interrupt inputs,
RS-232, 2x RS-485 for Profi-S-Net/MPI/S-Bus
Datasheet: 31-662_ENG_DS_PCD3M5540.pdf
PCD3.M5540