Renishaw RCU10, Installation And User Manual, Page: 107 / 202

B-16 Connector pinout and hardware installation details
A maximum allowable voltage drop of 1.25 V from the RCU10 to the sensor governs the
maximum allowable cable run. The specification for peak current drawn by any one
sensor is 20 mA, which means that for a single run of cable, the power lead resistance
must
be less than 31.25 Ω. Two examples utilising Belden 88102 are shown below:
•
For a single run: Belden 88102 has 24
AWG cores that give a resistance of 76 Ω per
km, which means a maximum single run of 400 m (see Figure B.5).
•
A common network with three equally spaced sensors (see Figure B.5): the cable to
sensor S1 is conveying 60 mA, the cable to sensor S2 is conveying 40 mA and the
last cable to S3 is conveying 20 mA. The total voltage drop is (0.06 + 0.04 +0.02) *
(2 * 203/3) * (76/1000) = 1.24, which gives a maximum run of 203 m in this
configuration.
Figure B.5 – Custom cables
S
24AWG
Total 400m
S3
24AWG
Total 203m
24AWG 24AWG
S2 S1