Fish

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  1. Hi, I am sorry, I feel like I should be able to resolve this from other posts, but it is not working for me. I am reading a voltage input on 6 AIN channels (Ch# 0-5) and I want to have a 5 volt output on 6 DACs (Ch# 0-5) depending on the corresponding AIN. I have a U6 Pro with a CB37 terminal board on which I have connected 3 LJTick DACs. I have figured out as much as that I need to run a sequence to define my 6 channels. Can anyone help me with that? As simple as possible preferably. Thanks.
  2. Hi again, I haven't been looking at this over the summer, but am now getting back to it, and I think perhaps my questions was misunderstood, or just poorly formuulated. I am thinking the sequence above gives me a time dependant variable output? In my setup, I can either have a solenoid open to add nitrogen gas to the water for the purpose of bringing down the oxygen saturation level of the water, or it can be closed. Its a NC valve, meaning normally closed, i.e. if there is no voltage on the output channel. My input channel is from an oxygen probe with a 0-5V output representing the range from 0-100% saturation. It runs through a conversion - value*20. At different times of the day I want to deoxygenate the water to different levels, as illustrated in the figure of the original post. In table form it looks something like this, with TOD = 0 being midnight and so on TOD O2 saturation 0 52 1 46 2 39 3 34 4 30 5 26 6 22 7 20 8 23 9 34 10 53 11 66 12 81 13 92 14 99 15 100 16 100 17 98 18 88 19 78 20 72 21 66 22 60 23 55 So, for example at midnight (TOD=0), the solenoid on Ch4 should switch on if O2 saturation increases above 52%, at 1 am it should switch on if O2 saturation is above 46%, and so on. At midnight it should repeat the loop. If there was also a way to implement a hysteresis of e.g. 2% below the setpoint that would be great. The is no oxygenation to the tank, but there is a constant supply of oxygenated water that will slowly bring up the O2 level in the morning hours. Thanks
  3. Thanks. I don't have a formula per se. I was thinking more that time could be part of the event code; adding several lines along the line of "if systime(>7200, but <14400) AND if input channel 1 (> xx volts), then output channel = 5 volts" and then just add the required number of lines. I apologize, I know this is probably a total rookie question...
  4. Hi guys. I am a low tech biologist user of DAQFactory. I have previously used it to control aeration and degassing of water based on input from gas probes. I am thinking about doing an experiment where I want to have daily variations in oxygen levels in a tank. I can hook up my Labjack with input from an oxygen probe and control if I want to keep levels above or below a certain threshold. Is it possible in that little bit of code to integrate time as a variable, so that I can ramp down oxygen levels to a set minimum value during the night, after which it slowly climbs back up? Any help would be greatly appreciated. My desired levels are illustrated in the attached image. Cheers
  5. I can pull up a settings menu through a hyper terminal and choose between PakBus, MD9 and transparent, so probably that's it, but I could try to send them a mail.
  6. Thought I'd take a pic of the physical installation if that might help... Closeup of the probe connections to the multiplexer and the first MD485 and power supply
  7. The sensors plug straight into the multiplexer relay (http://www.campbellsci.com/am16-32a) connected to a neighbouring MD485, which again is connected to another remote MD485 with a PC connection.
  8. As the title suggests, I have a series of 18 oxygen probes connected to a Campbell Scientific MD485 multidrop interface via a 32 channel multiplexer. The MD485 runs a PakBus communication protocol which I guess is unique to Campbell Scientific. I am guessing that this communication protocol rules out the possibility of using DAQ Factory to obtain my oxygen readings, but would appreciate anyone who has any knowledge or suggestions in this area. Thanks in advance.