Symetrix

TECH TIPS

DSPs and ARC-PS; adapting CAT5 for RS-485 Terminal Block

Figure 1Connecting ARCs to Jupiter hardware is simple using the (RJ-45) ARC port on either the front or back of the device. These ports not only provide communication (RS-485) data, but also +24 VDC power. If the required number of ARCs exceeds the current limits of the Jupiter ARC port(s), an ARC-PS can be used to power additional ARCs. Connecting a Jupiter ARC port to the RS-485 port on the ARC-PS is easily accomplished by following one of two methods.

Method 1: Modify an Off-the-Shelf CAT-5 cable

  1. Cut off one end of the CAT-5 cable.
  2. Wire three of the wires to a terminal block connector such that:
    A = Blue.
    B = Blue/White.
    Ground = Green.
    Note: Blue/White is twisted with Blue, and Green/White is twisted with Green.
  3. Connect the RJ-45 to the ARC port on Jupiter.
  4. Connect the terminal block connector to the RS-485 port on the ARC-PS.
  5. Connect your ARCs to the RJ-45 ports on the ARC-PS.
  6. Program your ARCs with the External Controller Wizard in the Jupiter software.

Method 2: Make Your Own Cable

  1. Crimp an RJ-45 connector to one end of a CAT-5 cable.
    Note: Only pairs 4+5 and 3+6 are necessary, so STP cable could be
    substituted by sharing the ground.
  2. Wire three of the wires to a terminal block connector such that:
    A = pin 4.
    B = pin 5.
    Ground = pins 3 and 6.
  3. Connect the RJ-45 to the ARC port on Jupiter.
  4. Connect the terminal block connector to the RS-485 port on the ARC-PS.
  5. Connect your ARCs to the RJ-45 ports on the ARC-PS.
  6. Program your ARCs with the External Controller Wizard in the Jupiter software.

FIgure 2.

Jebraan Gowani

Jebraan Gowani

Symetrix Technical Support Engineer

Document: 2010-07
First published: July 2010
Last Updated: November 2022

NOTE: Refer to the ARC Network Design topic in the Jupiter help file for more information.

NOTE: This Tech Tip does not apply for the ARC-PSE.

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