Emerson ROC827 - Manual (Page 56)

ROC827 Instruction Manual
Issued Mar-06 Power Connections 3-12
Table 3-6. Power Consumption of the Analog Input Modules
Power Consumption (mW)
I/O Module
Description P
TYPICAL
Quantity
Used
Duty
Cycle
Sub-Total
(mW)
ANALOG INPUT
AI Module Base 84 mA @ 12 volts dc 1008 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 AI channel’s current averages 16 mA:
Duty Cycle = Average mA output
÷ Maximum mA Output = (16 ч 20) = 0.80