Weidmuller WI-I/O-9-U2: Wireless Mesh I/O & Gateway User Manual V1.2.2 - Manual (Page 19)

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2.2.2 Expansion I/O Supply
To allow increased I/O Capacity, a second 4-
way terminal labelled “Expansion I/O”
provides a +12 Volt supply (up to 1A) and RS485 communications for any WI-I/O-EX-1-
S serial expansion I/O modules.
Figure 4 – Expansion I/O power & RS485
As a guide when using the I/O power connection from the WI-I/O 9-U2, the number of
I/O modules is limited to three x WI-I/O-EX-1-S-11(using inputs), one x WI-I/O-EX-1-S-
12, or one x WI-I/O-EX-1-S-13.
If more I/O Modules are required, you will need to calculate the overall current
consumption using the following criteria and power the modules from an external
supply.
WI-I/O-EX-1-S Module Static Current drain = 120mA
WI-I/O-EX-1-S Digital Inputs require 13mA per active input
WI-I/O-EX-1-S Digital Outputs require 25mA per active output
WI-I/O-EX-1-S Analog Inputs and Outputs require 50mA per I/O when operating at
20mA
E.g. a single WI-I/O-EX-1-S-11 using inputs only has a current consumption of
approximately 320mA so you could connect up to three WI-I/O-EX-1-S-11 modules to
the Expansion port without overloading the on board I/O power supply.
A single WI-I/O-EX-1-S-12 using all analog inputs and digital outputs has a current
consumption of approximately 720mA so you could only connect one.
Keep in mind that when calculating the current consumption for the expansion I/O, the
maximum available current from the onboard power supply is 1 Amp. If the overall
Expansion I/O current consumption is over the 1 Amp maximum an external power
source will be required.