The HCS-II controller board uses both RS-232 and RS-485 ports for communication. These ports are often connected to long runs of cables which can induces sizable surge voltages during electrical storms. The number one repair for HCS-II boards is blown serial chips. Some boards were damaged further due to the strength of the surge and the serial chip shorting out.
The help protect the HCS against damaging surges, you can replace your RS-485 and RS-232 serial chips with new Electric Static Discharge hardened ICs from Maxim. These chips can withstand discharges as high as 15,000 volts. The RS-485 chip also provides slew rate limiting which can improve the reliability of your RS-485 network. Slew Rate limiting helps reduce EMI and signal reflections on cables with improper termination.
