Upgrading a BAS NIU Type 3 to a Sigma DNN – Location of Communications Cards

[Product_Support]

Issue

Clarification is needed on the physical location and port assignments of communications modules when upgrading a BAS NIU Type 3 to a Sigma DNN.

Product Line

Satchwell BAS & Sigma

Environment

• BAS NIU Type 3
• Sigma DNN
• Communications Modules (ARCnet, Ethernet)

Cause

There are three available module slots in the DNN (formerly NIU). Understanding how these slots correspond to port numbers is essential for proper network configuration.

Resolution

Each module slot corresponds to a specific port number and network function:

• Top Slot → Port 1

  • Typically used for Sub-LAN connections
  • Example: ARCnet module installed here

• Middle Slot → Port 5

  • Typically used for Main Network connections
  • Example: Ethernet module installed here

• Bottom Slot → Port 6

  • Typically used for Backup Network connections
  • Often left unused unless redundancy is required

Visual Reference:
In the image below, the DNN is configured with:

• ARCnet in Port 1 (Top)
• Ethernet in Port 5 (Middle)
• Port 6 (Bottom) is vacant