American Access Systems ProAccess 200sa - Manual (Page 14)

SK-ACP Installation & Operating Manual
RS-485
The RS-485 bus is used to link multiple SK-ACP units into a network. Where two or more SK-ACPs are linked,
you must run cable between the “J8” plugs on each panel. Terminals 1 & 2 must be a twisted pair of wires.
SUGGESTED CABLE IS Belden 1585A. Terminal 3, if used, may be connected to one conductor of another
twisted pair. (Terminal 3 is a “signal ground”. If used, this must be an insulated conductor and it should NOT be
connected to earth ground.)
Where the distance from the p.c. to any one of the SK-ACP units is greater than 100’, you may install an RS-232
to RS-485 converter (Secura Key p/n NET-CONV-P) to the COM port of the computer. From the converter you then
run RS-485 cable and connect it anywhere along the RS-485 bus. The total RS-485 cable distance, including the
distance between all SK-ACPs, may be up to 4000’.
Figure 8 shows how each SK-ACP is connected to the RS-485 bus.
Earth Grounded Shield is highly recommended in environments subject to high voltage electrical discharge (ie.
lightning). Shield should be connected to earth ground only at one end of the cable. DC Signal Ground may be
necessary in networks with very long wire runs. DC Ground wire is NOT to be connected to earth ground.
FIGURE 8
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PROGRAMMING THE SK-ACP WITH SK-NET™
The SK-ACP must be programmed with SK-NET™ software. Please refer to the SK-NET™ manual for programming
instructions. (The SK-NET™ manual is available at www.securakey.com/manuals/SKNET_5879.pdf)