If you select a card link in the tree structure in the I/O Manager, you will receive further information on this connection.
”Link” area
In the Info tab, information about the FO communication is displayed in the left part. The displayed information depends on the current protocol on the FO link.
Communication status
“OK” if the FO communication is working without interference.
This means that the telegrams that are being received correspond with the mode that is configured on the link. The transmission mode is determined by the device (module) connected to the link. For example, the transmission mode is set to 3Mbit if an ibaPADU-8 is connected, or to 5Mbit for an ibaPADU-8-ICP.
Detected link protocol
Link protocol detected by the card
Possible values: 2Mbit, 3Mbit, 5Mbit, 32Mbit, 32Mbit Flex or "?" (no device connected).
Selected link protocol
Link protocol set for this link
It is determined by the attached module.
Telegram counter
Counter of correctly received telegrams
Error counter
Counter of telegrams received with errors (e.g. checksum errors)
If this counter reading changes, the fiber optic communication is not correct.
Time between telegrams
Time interval between the last 2 correctly received telegrams
“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 card writes into the PC system memory via DMA. This image contains all data of the measured signals on that link.
Here is a short description of 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 value should normally correspond with the interrupt time divided by the image sampling rate.
Images in DMA buffer
This is the number of images that are in the DMA buffer. This number should remain constant. If this number starts to increase, the system does not work correctly. This may happen if e.g. an interrupt is missed.
Images copied to interrupt buffer
This counter shows how many images have been retrieved from the DMA buffer and have been processed by ibaPDA. This counter should count up continuously.
DMA buffer empty
This counter increments each time the DMA buffer is empty when the interrupt fires. If this is the case, then the driver sets all signal values of the respective link to 0 (zero). This may happen if the FO link is disconnected.
Time between telegrams
Time interval between the last 2 correctly received telegrams
This is the same value as the time in the FO communication information but the driver maintains the minimum and maximum values. There shouldn’t be much difference between the minimum and maximum values.
Image sample rate
The rate at which the card writes images to the DMA buffer.
This should be faster or equal to the fastest time base of the modules connected to this link.
Image size (bytes)
Size of the image in bytes
If you multiply the image size with the image sample rate then you know how many bytes per second are transferred by this link over the PCI(e) bus.
Dropped images
This counter increments when the card’s DMA fifo is full and an additional image arrives. If this happens then something is seriously wrong. This means that the card is unable to transfer images over the PCI(e) bus.
DMA buffer size
Size of the DMA buffer for this interface
DMA buffer element size (bytes)
Size of the elements in the DMA buffer (in bytes)