Some pins are allocated for firmware upgrade possibilities of the Embedded RC232 protocol. See Data sheet page 19 for details at https://www.radiocrafts.com/uploads/rc11xx-rc232_data_sheet_1_42.pdf. How to firmware upgrade the module is described in AN012 at https://www.radiocrafts.com/uploads/an012_firmware_upgrading_the_rc1180_mbus_module_1_0.pdf.
Last Update: August 8, 2017
December 13, 2016 1846 RC232 Q&A