Campbell Scientific MD485 RS-485 Multidrop Interface - Manual (Page 36)

Appendix B. RF401 to MD485 Network
B-8
5. HARDWARE
After configuring LoggerNet or PC208W, the RF401s and the MD485s
you are ready to set up hardware. Connect the base RF401 RS-232 port to
the PC COM port. Attach the null modem cable to the RS-232 ports of
the remote RF401 and the base MD485. Attach transformers to the DC
Pwr jack of each RF401 and the base MD485.
Remote MD485s normally connect to datalogger CS I/O ports via SC12
cables. Powering up the datalogger will start the MD485 operating.
Connect the CABLE2TP cable between the RS-485 ports of the base and
remote MD485s and you are ready to connect to the datalogger.