The network data riser provides the communication path between each CPU module.
(( you will need to install the RS-485 board))
The correct method for running the network data riser is to connect the B port on one CPU to A port on another.
Note: Since the data traveling the network data riser is bi-directional, out and in references are used to direct wire connections.
Class B network data risers
The service panel is the panel you download from, the A out with no wires on is the service panel
Class A network data risers
Download connections via modular phone jack via class B network, this will not work
Each programmable rail module has a modular phone jack to use for downloading data directly.
The Network A port and its modular phone jack share an interrupt.
In addition to the modular phone jack, the CPU module has two serial communication ports that can be used to download data.
• A 3-RS232 option card is installed
• The serial port used to download data is not configured for gateway or coder applications
Note: Connecting the SDU computer to an optional serial communications port does not affect the Network A port. If a 3-RS232 option card is connected to the CPU, you can download data to any panel on a Class B network regardless of where the panel physically connects to the network data riser
.Download connections via modular phone jack via class A network
On Class A networks however, see Figure 1-14, disabling the Network A port on panel B1_CAB3 does not prevent the other panels from receiving data through B1_CAB3’s Network B port.