Wayne, you asked on Tue, 20 Jan 2004 15:47:36 GMT: > I have a PXI-1010 chassis with a 8175 controller and three PXI-6070E DAQ cards. I am > measuring 16 channels per > card. I receive an error 10845 from NI-DAQ LV stating "Because of system and/or > bus-bandwidth limitations, the > driver could not read data from the device fast enough to keep up with the device > throughput; the onboard device > memory reported an overflow error". The error occurs when reading the first channel > of the next device when the > devices are in adjacent slots. The devices are in slots 8,7,6. If I move the devices > to slots 8,6,4 then no error > occurs. I have to support 6 PCI-6070 devices in the future, so leaving empty slots > will not be an option. We are > running Win 2000 and LabVIEW 7. This error occurs for sampling rates >20K per > channel. > > Has anyone seen something like this before? I have also a PXI-1010, but with exchanged fans and a MXI-3-(copper)-connection to my PC. I had a look on NIs pages and found that a 6070E card is a 16ch*12bits*1,25MS/s AI card with 2ch AO at 12 bit and 1MS/s. Quite impressive! Are you sure you can transfer all those data trough the slot bus, the 8175 controller AND your LAN connection? Even when sending the data as binary you get 16ch*2Bytes*1,25MS/s, which adds up to 40MB/s juat for one cards AI part. Those cards feature a buffer of just 512 Samples, which is filled up about 2500 times per second. ALso quite impressive, but your controller should be able to handle this. The PXI bus has 6 trigger lines, so at principel your cards should be able to be put into an independend operation mode. This might be the problem that your cards are 'considered as one -stacked- device' when put aside each other in the chassis and as single devices when separated by empty slots. This would make the timing even harder for the controller.
You may call/mail NI asking for a hint on how to setup those cards as individual devices. I am still not convinced that this huge amount of data can be transferred to an external PC. If you have all 6 cards together you get 240 MB/s. Thats far beyond any standard LAN speed (don't expect more than about 5MB/s net transfer rate on a 100Mb LAN connection). Even good HDs can not store more than about 10MB/s continuously. So the only solution I imagine is enough RAM in the controller to temporarily store your data and transfer it afterwards. Hope I did not misunderstand anything. Greetings from Germany! -- Uwe Frenz ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dr. Uwe Frenz Entwicklung getemed Medizin- und Informationtechnik AG Oderstr. 59 D-14513 Teltow Tel. +49 3328 39 42 0 Fax +49 3328 39 42 99 [EMAIL PROTECTED] WWW.Getemed.de
