Emerson ROC827 instruction manual Power Consumption of the Analog Input Modules, Used Cycle

ROC827 Instruction Manual

Table 3-6. Power Consumption of the Analog Input Modules

I/O Module	Power Consumption (mW)		Quantity	Duty	Sub-Total
	Description	PTYPICAL	Used	Cycle	(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 ⎟ 20) = 0.80

Issued Mar-06 Power Connections 3-12