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Emerson ROC827 User Manual

Page 57

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ROC827 Instruction Manual

Issued Mar-06

Power Connections

3-13

Table 3-7. Power Consumption of the Analog Output Modules

Power Consumption (mW)

I/O Module

Description P

TYPICAL

Quantity

Used

Duty

Cycle

Sub-Total

(mW)

AO Module Base

100 mA @ 12 volts dc

1200 mW

Jumper set for +T @ 12 volts dc

Channel 1

Channel’s mA current

draw from +T * 1.25 * 12

Channel 2

Channel’s mA current

draw from +T * 1.25 * 12

Channel 3

Channel’s mA current

draw from +T * 1.25 * 12

Channel 4

Channel’s mA current

draw from +T * 1.25 * 12

Jumper set for +T @ 24 volts dc

Channel 1

Channel’s mA current

draw from +T * 2.50 * 12

Channel 2

Channel’s mA current

draw from +T * 2.50 * 12

Channel 3

Channel’s mA current

draw from +T * 2.50 * 12

Channel 4

Channel’s mA current

draw from +T * 2.50 * 12

Table Total

Duty Cycle

The duty cycle is based on the average current flow compared to the
full-scale current flow value. To approximate the duty cycle, estimate
the average current consumption in relation to its maximum range. For
example, if an AO channel’s current averages 12 mA:

Duty Cycle = Average mA output

÷ Maximum mA Output = (12 ч 20) = 0.60