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Connecting expansion units with SPCN cables

Use these instructions to learn how to connect expansion units into the system power control network (SPCN).

Find the SPCN cables that were included with your expansion units.
Review Examples: SPCN connections and then return here and continue with the instructions.
Important: As noted in Overview for I/O expansion units, there is only one SPCN loop per system to which all expansion units are connected.

Choose from the following options:
- To add expansion units when there is not already an SPCN loop, go to step 2.
- To add expansion units to the beginning of an existing SPCN loop, go to step 3.
- To add expansion units to the middle of an existing SPCN loop, go to step 4.
- To add expansion units to the end of an existing SPCN loop, go to step 5.
To add expansion units when there is not already an SPCN loop, do the following:
1. Connect an SPCN cable to connector SPCN0 on your system unit.
2. Connect the other end of the SPCN cable to connector SPCN 0 on one of the expansion units to be added.
3. Connect another cable to connector SPCN 1 on the expansion unit added in step 2.b.
4. If there is another expansion unit to add, do the following:
  1. Connect the other end of the cable from connector SPCN 1 on the expansion unit just added to connector SPCN 0 on the next expansion unit.
  2. Connect another cable to connector SPCN 1 on the expansion unit added in step 2.d.i.
5. Repeat step 2.d for each additional expansion unit to be added.
6. Connect the other end of the cable from connector SPCN 1 on the last expansion unit added to connector SPCN1 on your system unit.
7. Return to the procedure that sent you here.
To add expansion units to the beginning of an existing SPCN loop, do the following:
1. Remove the SPCN cable end from connector SPCN 0 on the first expansion unit (the one connected to connector SPCN0 on the system unit). Reconnect this cable end to connector SPCN 0 on one of the expansion units to be added.
2. Connect another SPCN cable to connector SPCN 1 on the expansion unit added in step 3.a.
3. If there is another expansion unit to add, do the following:
  1. Find the other end of the cable attached to connector SPCN 1 on the expansion unit just added. Connect this end to connector SPCN 0 on the next expansion unit to be added.
  2. Connect another cable to connector SPCN 1 on the expansion unit added in step 3.c.i.
4. Repeat step 3.c for each additional expansion unit.
5. Find the other end of the cable attached to connector SPCN 1 on the last expansion unit added. Connect this end to connector SPCN 0 on the expansion unit that was disconnected in step 3.a.
6. Return to the procedure that sent you here.
To add expansion units to the middle of an existing SPCN loop, do the following:
1. Remove the SPCN cable end from connector SPCN 0 on the expansion unit that will follow the expansion units that are being added. Reconnect this cable to connector SPCN 0 on one of the expansion units to be added.
2. Connect another SPCN cable to connector SPCN 1 on the expansion unit added in step 4.a.
3. If there is another expansion unit to add, do the following:
  1. Find the other end of the cable attached to connector SPCN 1 on the expansion unit just added. Connect this end to connector SPCN 0 on the next expansion unit to be added.
  2. Connect another cable to connector SPCN 1 on the expansion unit added in step 4.c.i.
4. Repeat step 4.c for each additional expansion unit.
5. Find the other end of the cable attached to connector SPCN 1 on the last expansion unit added. Connect this end to connector SPCN 0 on the expansion unit that was disconnected in step 4.a.
6. Return to the procedure that sent you here.
To add expansion units to the end of an existing SPCN loop, do the following:
1. Move the SPCN cable from connector SPCN 1 on the system unit to connector SPCN 0 on one of the expansion units to be added.
2. Connect another SPCN cable to connector SPCN 1 on the expansion unit added in step 5.a.
3. If there is another expansion unit to add, do the following:
  1. Find the other end of the cable attached to connector SPCN 1 on the expansion unit just added. Connect this end to connector SPCN 0 on the next expansion unit to be added.
  2. Connect another SPCN cable to connector SPCN 1 on the expansion unit added in step 5.c.i.
4. Repeat step 5.c for each additional expansion unit.
5. Connect the other end of the cable from connector SPCN 1 on the last expansion unit added to connector SPCN 1 on the system unit.
6. Return to the procedure that sent you here.

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Last updated: Tue, September 30, 2014