6GK1500-0AA00 6GK15000AA00 card rs485 bus terminal 6GK1 500-0AA00 500-0AA00 SIEMENS 6GK1500-0AA00 6GK1500 0AA00 Siemens SINEC L2 bus terminal SIMATIC NET RS-485 bus terminal PROFIBUS RS-485 module Industrial communication module Siemens Siemens bus interface SIMATIC NET 6GK1500 bus terminal PROFIBUS Legacy S5 communication module Siemens Siemens automation interface module PLC PROFIBUS RS-485 module Siemens Siemens industrial networking module