Chuck- Thanks again so much for the help; I've added comments to the quote below. Please let me know if there's anything else than can be useful!
chucktodd:
Reading through the manual, What are the values for the following 'Windows"M46 - 1
M49 - shows whatever I send via Arduino IDE Serial
M52 - 0. Internal SerBus
M62 - 9600,None,8,1
M63 - MODBUS ASCII+ TDS7 (though I've changed this to try RTU with no luck either)Chuck