ADLINK PCIe-7350 - Manual (Page 25)

Hardware Information 15
2.3 LED indicator
There are two LEDs on the bracket which display the I2C & SPI
communication and digital I/O status of the PCIe-7350.
Table 2-4: LED indicator
LED Color Mode
STS 
(Status)
Red I
2
C mode enabled
Yellow SPI mode enabled
ACC 
(Access)
Red DI DMA operation
Yellow DO DMA operation
Amber DI & DO DMA operation