communication between RCM3100 and PC?????????

Hi, i’m new on this and i’m a bit lost…
I want to communicate my PC to my RCM3100 with RS 485, with the programming port. but i look that the programming port has CMOS.I think i have to convert RS485 from my PC to CMOS,but the solution is very expensive because this project is a solution for a lot of boards, and every conversor costs $50 aprox.
is there any other solution easier,and cheaper?

You can use RS-485 transceiver such as the SP483E to convert the signal. It will cost you around 2$ - 3$ per chip. Use “RS485 transceiver” to search at mouser. Let me know if you need custom PCB board for RCM that come with RS485, regulator and connector. We’ve done it before.