Expansion Power Unit must be used on every 12th module in an isysnet assembly.

The 24VDC expansion power supply unit (PSSSE24A) passes 24VDC field power to the I/O modules to the right of the power supply. This unit extends the backplane bus power for up to 17 I/O modules to the right of the supply and creates a new field voltage partition.

The expansion power supply also separates field power from I/O modules to the left of the unit, effectively providing functional and logical partitioning for:

• separating field power between input and output modules
• separating field power to the analog and digital modules
• grouping modules to perform a specific task or function

You can use multiple expansion power units with the I/O adapters to assemble a full system.