6200 series Operations Manual
Rev D 2/14/2012
Page 15 of 60
RS-485 communications are intended to communicate with a PC using ModBus RTU
or Standard Bus. The maximum number of chambers connected to a single PC is
limited to 247 controllers (Modbus) or 16 controllers (Standard Bus). Chambers 6221
& 6421 have one controller each. Chambers 6220 & 6420 have two controllers each.
Connect shielded wires to the RS-485 Communications terminal blocks.
Communications wires should be shielded and routed away from power wires.
Maximum distance of total wire is 2000 feet. When connecting multiple chambers,
route wires in a daisy chain fashion. A termination resistor of 120 ohms may be placed
across RS-485(-) and RS-485(+) of the last chamber in the daisy chain.
For PC’s having an RS-232 serial port (9-pin D-Sub) connection, an RS-485 to RS-232
converter may be used. Recommended sources are B&B Electronics (P/N 4850I9TB)
and CMC-Connecticut Micro Computer (ADA485L).
SFTW301 software is available from CARON to load onto a PC to monitor and record
data. This data storage is not 21CFR Part 11 compliant.