- From: Anne Smorthit <annesmorthit_at_hotmail.com>
- Date: Fri, 31 Jan 2003 12:23:38 +0000
Please excuse the rambling explanation, but I am fairly new to Linux, Comedi and data acquisition in general. We are trying to develop a Fast DAQ System which has at least 32 simultaneous analogue inputs, plus digital inputs and counter/timers. Currently we have identified some cards which would meet the hardware requirements, but as none of them have linux drivers we are planning to write comedi drivers. The analogue acquisition events start_src and scan_begin_src need to be in response to external triggers, which will usually be digital inputs. As we work in a noisy environment, the digital inputs will need to go through some form of signal conditioning unit. The signal conditioning unit generates an interrupt when a digital input changes, it does not have any outputs. We have an analogue card which has an external clock input and an external gate input. Ideally these could be used for scan_src and scan_begin_src respectively. As we don't have any outputs from the signal conditioning card, we need to use it's interrupt to start the acquisition on the analogue board. We do not want to respond to the interrupt in user space as this will generate too great a time penalty. Can we do this in kernal space? Can you give us some ideas of where to look for information? Is it possible to write one driver to control two cards (same supplier) so that the analog input from one card is one subsystem and the digital input from a different card is another subsystem? Anne Smorthit _________________________________________________________________ Help STOP SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail
Received on 2003-01-31Z12:23:38