COM Port Usage
The EC-NPB-2X-485 option card has two onboard
UARTs, and so adds two COM ports on the installed
EC-BOSAX controller. The hosted station
automatically resolves the option’s COM addresses.
• If an EC-BOS-2/3/6AX or EC-BOSAXSecurity
controller and installed in Option Slot 1, or if the
only option card, ports are COM3 and COM4.
• If an EC-BOS-7AX controller and installed in Option
Slot 1, or if the only option card, ports are COM5 and
If installed in Slot 1 of an EC-BOSAX along with another
option card that uses COM ports in Option Slot 2, note
that COM assignments for that other card are affected.
For example, if an EC-BOS-2/3/6AX with an
EC-NPB-2X-485 option installed in Slot 1, and a single
port RS-232 option installed in Slot 2, COM assignments
are: Slot 1 (RS-485): COM3, COM4, Slot 2 (RS-232):
The same option card mix in an EC-BOS-7AX controller
yields: Slot 1 (RS-485): COM5, COM6, Slot 2 (RS-232):