With no change to associated computer hardware or software, the device, called ADAM-4520A, transparently converts RS-232 signals to RS-422 or RS-485.
It “allows users to take advantage of RS-422 and RS-485 on systems originally equipped with RS-232”, said Advantach. “It can extend the communication distance by 4,000ft [1.2km] or increase the maximum number of connected nodes by 32.”
Externally-accessible DIP switches on one end of the case select: RS-422 (four-wire) or RS-485 (two-wire), switch on internal 120Ω termination resistors and change RS485 DIR from auto to RST. LEDs indicate data flow direction.
Up to 115.2kbit/s can be handled, and a DB9 connector (for a straight pin-to-pin cable) is provided for RS-232 while the rest of the connections are through a terminal block.
Power needs are +10 to 48Vdc, which can be unregulated (max ripple 200mV peak-to-peak). Consumption is typically 600mW at 24V (800mW max), and the input is reverse polarity protected. The isolation barrier is rated to 3kVdc.
Measurements are 102 (plus connectors) x 70 x 46mm – the latter with the included DIN-rail mounting bracket attached. A panel-mount bracket is also included.
Operation is over -40 to 85°C and the unit has a two-year warranty.
