In this case, 360mA at 5V power is available for any I/O expansion, to enable the USB port and for
COM/Vision power.
In this example, the total input power required from a 12V power supply is calculated as follows:
5V Power:
5V x .84A = 4.2W
24V Power:
24V x .14A = 3.36W
Total Input Power Required = 7.56W/0.85 = 8.90W (assuming 85% power supply efficiency).
Therefore your 12V power supply must be capable of providing 8.90W/12 = 0.74A of current.
Note that the additional analog input channels on the integrated 5606 I/O module will need to be
powered from an external power source.
Example 2
: Assume we have a 5209 controller board with two analog outputs but without the
integrated 5606 I/O module. The controller board is powered from a 12V supply, is operating in
reduced power mode and the LAN port is also not enabled. All five 20mA analog input channels on
the controller board and two optional 20mA analog output channels are needed. To power the
analog inputs and outputs using the controller board power supply, the 12/24V DC/DC converter
must be enabled. The current requirements in this scenario is summarized in the table below
5V Current
24V Current
5209 Controller Board
(base current in reduced power mode
)
40mA
20mA x 5 = 100mA (Vloop)
5305 Analog output
0mA
20mA X 2 = 40mA (Vloop)
Total 40mA
140mA
(operation)
Available for I/O expansion,
LAN, USB and COM/Visions
1160mA
remaining 1.2A
capacity
0mA
In this case, 1160mA is available to power the LAN and USB ports, COM/Vision displays as well as
other expansion modules downstream the SCADAPack 350 controller.
The total input power required from a 12V power supply is calculated as follows:
5V Power:
5V x 0.04A = 0.2W
24V Power:
24V x .14A = 3.56W
Total Input power required = 3.56W/0.85 = 4.19W (assuming 85% power supply efficiency)
4.3 System
Grounding
In most applications, it is desirable to ground the system by connecting the system power supply
common, to the chassis or panel ground. The negative (–ve) side of the DC power input terminal as
well as all I/O point terminals labeled GND are connected to chassis ground.
4.4
Power Management Features
The SCADAPack 350 provides a number of special features to reduce power consumption. Refer to
for an overview of the power management features. These power
management features are:
•
COM3 serial port power control for Vision Displays
•
VLOOP power control.
SCADAPack 350 Hardware Manual
February 14, 2007
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