Rockwell Automation Allen-Bradley ArmorBlock 1732E-IB8M8SOER User Manual page 25

the left. A female connector on the right is also provided so that power can be
daisy-chained from module to module.
Both modules require two 24V DC (nominal) supplies. These supplies are called
the Module Power and the Auxiliary Power. The Module Power powers the
microprocessor and Ethernet portions of the module. The Auxiliary Power
provides power for the Digital Outputs, the Digital Inputs, and the Sensor
Voltage.
Internally, the Module Power and Auxiliary Power are isolated from each
other.
The Module Power current required for a module can be estimated as 2.4W/
(Module Power Voltage). For example, if the Module Power Voltage is 24V DC,
then the Module Power current (Imp) would be,
Imp ~ 2.4W/24V DC = 100 mA DC
If the power for four modules were daisy-chained together and the voltage is
24V DC, then the Module Power current through the first connector in the
daisy-chain would be 4 x Im ~ 400 mA which is less than 4 A, so Module Power
current is within acceptable limits.
The Auxiliary Power current is more complicated. The equation is below:
Iap ~ Iapm + Isp0 + Isp1+ Isp2+ Isp3 + Isp5+ Isp5 + Isp6 + Isp7 + IDO0 +
IDO1 + IDO2 + IDO3 + IDO4 + IDO5 + IDO6 + IDO7 + IAPDC
Where:
• Iap is the Auxiliary Power current through the first connector in the
daisy-chain.
• Iapm is the Auxiliary Power current required by the module itself.
• IspN is the Sensor Power current for Digital Input N (0...7).
• I is the Digital Output current for Digital Output N (0...7).
DON
• I is the Auxiliary Power current requirement for the remaining
APDC
modules in the daisy-chain.
• Iapm can be approximated by 0.5W/(Auxiliary Power Voltage).
Rockwell Automation Publication 1732E-UM003D-EN-E - November 2021
Chapter 4 Install Your Module
25