... of computer serial prot or q ' ty of 485hub port, support 256pcs ports Operation Temperature - 40 C~70 C Operation Humidity ... 3000m TCP/IP: Depends on net coverage area Collocations PCB board, case, power, power line, serial port communication line, software, ... able to alarm by hardware, if connected with strengthened expansion board, then is able to Security alarm ( function(){ var aBigImageSrc = [ ' ...