IEPE function of 4474 Board does not run at industrial board?

[Youngkey]

I found that 4474's IEPE function does not work in my industrial 5.25" PCs. With my PCs, 4474 supplues 8V as IEPE supply voltage which is lower than normal 24V. As results, my accelerometer does not work. I cheked my 4474 board in my normal desktop PC, it supplies 24V and works fine. Without IEPE function, it works fine in both systems.

Is there any limitation in using 4474 with industrial mini computer?

I tested at two PCs:
1) ADVANTEC PCM-9580 (http://www.advantech.com/local_inc/search_to_fulltextsearch.asp?id=1002129&keywords=PCM+9580&pageid=r&mode=ALL)
2) Mini ITX Board with following specification
- CPU: Intel Pentium 4-M CPU up to 2.8 GHz @ 400 MHz FSB On-die 512KBytes Full-Speed Level 2 (L2) cache
- FSB: 533MHz/400MHz
- Chipset: Intel® 845GV chipset
- LAN Chipset: Realtek 8100BL LAN Controller (10/100Mb)
- Sound Chipset: ICH4 integrated audio with AC97 Codec ALC 650 6-Channel
- VGA Graphic: Intel® 845GV chipset integrated, AGP 4X
- Multi I/O Winbond 83627HF supports IrDA x 1, Parallel x 1, COM1, COM2 (RS232), FDC up to 2.88MB (3 Mode support), hardware monitoring Fintek 81216D supports COM3, COM4 (RS232)Built in ICH4
- IDE1: 40-pin box header (Ultra DMA 33/66/100)
- IDE2: 44-pin header
- Memory Slot: 1* 184-pin DIMM socket Support up to 1GB PC200/266/333 DDR SDRAM
- Expansion Slot: 1 PCI, support 2 bus master
- MB850MF TV out or LVDS, Intel® Pentium® 4 processor-M
- Form Factor: MINI-ITX
- Size: 17.0*17.0(cm)

[RossC]

Youngkey,

The only reason I can think of that the 4474 would not supply an adequate excitiation signal is if the power supply for the computer was not providing adequate power. The power requirements for the board can be found in the NI 447x Specifications and are as follows:

Rail	Current Required
+3.3V	0 mA
+5V	2000 mA, max
+12V	120 mA, max
-12V	120 mA, max

As long as these requirements are met, there is no reason that it should not provide the proper excitation signal.

Sincerely,

Ross C
Applications Engineer