Maximum cable length for ss200 communications – Wavetronix SmartSensor Advance Extended Range (SS-200E) - User Guide User Manual

Page 142

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APPENDIX 141

If the cable length is longer than 600 ft. (182.88 m) when operating at 24 V, it is possible to

increase the maximum cable length by wiring a pair of lines normally used for RS-232 com-

munications with the red and black wires.

If the cable length is 200 ft. (61 m) or greater you cannot reliably use RS-232 communica-

tions. 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 de-

sire 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 B.5.

Maximum Cable Length for SS200 Communications

To achieve reliable wired communications, the selected baud rate must be compatible with

the length of the cable run. The table below shows the cable length recommendations for

wired communications (see Table B.5):

Baud Rate

RS-232

RS-485

115.2

40 ft. (12.2 m)

300 ft. (91.4 m)

57.6

60 ft. (18.3 m)

600 ft. (182.9 m)

38.4

100 ft. (30.5 m)

800 ft. (243.8)

19.2

140 ft. (42.7 m)

1000 ft. (304.8 m)

9.6

200 ft. (61 m)

2000 ft. (609.6 m)

Table B.5 – 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.

Given the power and communcication requirements listed above, here is a summary of

some power and communication cable guidelines (see Table B.6).

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