RC22 PV reference cells may be retrofitted into installations originally designed for using RC18 PV reference cells in digital output mode via Modbus RTU (RS485).

For mounting and cabling of an RC22 unit in an RC18 installation, please order the 810298 adapter kit, which includes:

  • 610506 adapter plate, RC22-to-RC18  
  • 830296 adapter cable, M12 5-pin Male to M12 8-pin female  

The 610506 adapter plate, shown below, mounts to the bottom of RC22 and provides a footprint and user mounting holes that match the RC18.

610506 RC22 to RC18 Mounting Holes Adapter Plate

To use the 610506 adapter plate, first remove the Standard Mounting Plate which shipped with your RC22 (see RC22 User Guide), then use the screws which held the Standard Mounting Plate to install the 610506 adapter plate. 

RC22 Mounted on 610506 Adapter Plate

When RC22 is assembled on the adapter plate as shown, connect the 830296 adapter cable to the RC22's M12 5-pin input. The 8-pin end of the cable will now connect to the Atonometrics M12 8-pin cable series listed in the RC18 PV Reference Cell User Guide.

For data logging, note that the RC22 Modbus RTU registers for Irradiance, Isc, and PV Cell Temperature are identical to those for RC18 (see RC22 User Guide for the register table).