Wavetronix SmartSensor 105 (SS-105) - User Guide - Manual (Page 97)

96 APPENDIX • SMARTSENSOR 105 USER GUIDE
If the cable length is 200 ft. (61 m) or greater you cannot reliably use RS-232 communi-
cations. To add 400 ft. (121.9 m) and achieve a maximum cable length of 1000 ft. (304.8
m), connect the orange wire (normally RTS) to the red wire and the brown wire (normally
CTS) to the black wire.
If your cable run is longer than 1000 ft. (304.8 m), it is possible to sacrifice additional com-
munication pairs to increase the maximum cable length for power. However, you may desire
to communicate to the sensor over two independent channels, in which case you will need
to consider an alternate cable for power. The AWG for wire pairs that achieve a 2000 ft.
(609.6 m) maximum cable length or greater at 12 and 24 V are listed in Table A.5.
To achieve reliable wired communications, the selected baud rate must be compatible with
the length of the cable run. Table C.2 below shows the cable length recommendations for
wired communications:
Baud Rate (bps) RS-232 RS-485
115200 40 ft. (12.2 m) 300 ft. (91.4 m)
57600 60 ft. (18.3 m) 600 ft. (182.9 m)
38400 100 ft. (30.5 m) 800 ft. (243.8)
19200 140 ft. (42.7 m) 1000 ft. (304.8 m)
9600 200 ft. (61 m) 2000 ft. (609.6 m)
Table C.2 – Maximum Cable Length for Wired Communications
To provide two independent communication channels with a homerun cable length over
200 ft. (61 m), convert the RS-232 data into RS-485 using a Click 304 in a pole-mount
cabinet mounted next to the sensor. In this case, the homerun connection establishes one
RS-485 channel over the normal white/blue wire pair and another RS-485 channel over
the yellow/violet wire pair. An additional Click 304 is needed to convert the data sent over
the yellow/violet wire pair back to RS-232 before connecting to surge protection.
If you elect to use an alternate cable for power, you may also want to select an alternate
cable for RS-485 communications. Some options include the Belden 3105A (Paired – EIA
Industrial RS-485 PLTC/CM) or Alpha Wire 6010C 3PR 22 AWG.
There are many reliable options available for wired power and communications connections
(see Table C.3).
Length Cable Comm. Channel 1 Comm. Channel 2
0–200 ft. (0–61 m) 8-conductor Cable Native RS-485 Native RS-232
200–1000 ft.
(61–304.8 m) 8-conductor Cable Native RS-485 Click conversion of
RS-232 to RS-485
1000–1400 ft.
(304.8–426.7 m) 8-conductor Cable Native RS-485 N/A