... CPU Unit connector Front Back (CIF11) Back (CIF12) SW 1 123456 ON 1234 ON 12 ON SW 1 SW 2 COMM RDA- RDB+ SDA- SDB+ SHLD RS-422A/485 Terminal Block RDA- RDB+ SDA- SDB+ SHLD * For two...https://www.ia.omron.com/data_pdf/cat/nx1p_p116-e1_9_8_csm1055399.pdf