Manual
ibaDAQ
48
Issue 1.1
FO signal strength
This is the difference between the maximum value and the minimum value received
from the FO unit. It can be 255 max. The higher this value, the stronger the FO in-
put signal.
Device ID
The ID of the last device in an FO series connection at this FO interface.
Telegram format
This is the format of the analog data transferred in the telegram. "Integer", "Real"
and "S5 real" are possible formats.
"Image generation" area
The information on the right side of the dialog describes the image generation (process
image). An image is a collection of bytes that the board writes into the computer memory
via DMA. This image includes all data of the measured signals on that link.
The following list explains the image generation information:
Images processed at interrupt
These counters show how many images were available in the DMA buffer when the
last interrupt fired. This should normally correspond with the interrupt time divided
by the image sampling rate.
Images in DMA buffer
This is the number of images available in the DMA buffer. The number should be
constant. If this number increases, the system does not work correctly. This can be
a missing interrupt for example.
Images copied to interrupt buffer
This counter shows how many images have been read from the DMA buffer and
processed by ibaPDA. This counter should gradually count upwards.
DMA buffer empty
This counter increments each time when the interrupt fires while the DMA buffer is
empty. If this is the case, the driver will set all signal values of the respective port to
zero (0). This can happen for example if the FO link is interrupted.
Time between telegrams
The time between the last 2 correctly received telegrams. It is the same value as in
the left section of the dialog box, but additionally specifies the maximum and mini-
mum distance. The differences between min. and max. value should not deviate
significantly from each other.
Image
sample rate
The rate at which the board writes images to the DMA buffer. It should be greater
than or equal to the fastest acquisition rate of the modules connected to this link.
Image size
This is the image size in bytes. If you multiply the image size with the image sample
rate, you know how many bytes per second are transferred by this link over the PCI
bus.
Dropped images
This counter increments when the card’s DMA fifo is full and additional images are
added. This is a serious problem. The card cannot transfer images over the PCI
bus.
