I am using a CR800 to control a water smapler via a control port. I want the control port to turn on when the water level (Stage_avg) exceeds activation stage (Act_stage). The language below does that, however, I need the control port to stay high until I physically reset it. I want the sampler to run longer than it takes for the stream water level to go below activation stage With the language below, CP2 turns off when the water level is less than activation stage, exactly as the code is written.
If (Stage_avg >= Act_stage) Then
PortSet(2, 1)
Delay(0,1,Sec)
Else
PortSet(2, 0)
EndIf
Could someone provide additional code or a different instruction to do this?
Thank you.
If you delete the lines of code:
Else
PortSet(2,0)
then your sampler will never turn off, once the control port is set high.
Depending on how you plan on resetting the sampler physically, you could add a manual trigger to set control port 2 back to 0.
eg
public ResetPort as boolean
If ResetPort = True then PortSet(2,0)
Thank you sjp. I got the program to work.
OK. I am confused with this.
I can run the program on my desk with just the logger and a CS450 and get it to run as I want. The CP port is low until the threshold is crossed and stays high until I manually reset it.
In the field, I am using CP2 to control an ISCO automated sampler that runs its own equal time increment program once CP2 is high (until CP2 is reset or the ISCO program is done). I am using a CSI sampler control cable between the CR800 and the 3700 sampler. With the sampler control cable, the wiring is the same as we have always used with the CR10X (Green to CP, and clear/purple to ground). The other wires are not used.
The mystery comes when I hook up the sampler control cable. As soon as I wire in the green wire of the sampler control cable, CP2 immediately goes high and immediately goes low once I remove the gren wire. I do not get this response when I just close CP2 (empty), nor when I tested using the clear wire from the sampler control. I run 2 samplers, and had access to a second sampler control cable and it does the exact same thing with the green wire immediately turning CP2 high on contact.
This is the first time I am trying to use the CR800 and sample control cable in this configuration. I can't point to where my issue stems from.
Does anyone have advice on this?
I sounds like the sampler control pin is tied high internally in the sampler. This would make sense if the input was designed for something like a switch closure on a tipping bucket rain gage. If so, the sampler is probably expecting you to pull the control pin low (to a common ground).
How is the control port different on the CR800 from the CR10X? I have everything on the sampler control cable and ISCO sampler set up as we did with the CR10X. On the CR10X, the control port stayed low until the program turned it high. With the CR800, I can not get the cpntrol port to go low when the sampler control cable is connected.
I seem to remember I had a similar problem with a CR206X and the ISCO sampler control cable.
I had the CR206X controlling two different ISCOs and when I hooked up the second ISCO, I had problems. As in your case, the control port would not go low. I solved it by hooking up a resistor (I think it was a 3.3 K) somewhere. I don't remember exactly where in the circuit the resistor went, but it solved the problem. Maybe someone with more knowledge of circuits can explain why this worked or where the resistor actually went (I'll look through my notes to see if I can find it).
The control port is pulled down to ground internally via an internal resistor. If The port is high either a) the logger is setting it high with the portset() or writeio() instructions or b) the isco is driving the port high. If you are confident in your program, then I suggest the difference is in how you are connected to the sampler or the sampler interface configuration. I suppose you could try lespedeza's suggestion of putting a high valued resistor between the control port and ground. However, if this works I would question if the input has been previously damaged and left floating.