Water Level monitoring with CAI Webcontrol

[swaggy]

I am finishing a basement and have this corrugated pipe that's about 5" in diameter in the corner:

I never really paid any attention to it until I started finishing the basement and now I am trying to figure out what to do with it. I looked inside with a flashlight and there's standing water about 6" below surface. I never had water in the basement (although we've only been in this house for year and a half) so not sure if this is something I need to worry about. Regardless, I'd like to monitor the water level inside this pipe and alert on it, ideally using a CAI Webcontrol board. I bought a GRISK 2600 sensor to try with my OmniProII but I don't think it will work with the Webcontrol. Looking for some thoughts or suggestions..

Thanks

 

[CAI_Support]

Hi Swaggy,

The sensor you mentioned will work in certain way. It will not indicate the water level, but it can tell you the water reached the level where the sensor is located. You can wire its dry contact between 5V and WebControl TTL Input 1, then put this program in the PLC code:

START
SET RAM1 0
LOOP:
TSTGE IP1 1
GOTO SEND
SET RAM1 0
GOTO LOOP
END
SEND:
BNZ RAM1 LOOP
SET RAM1 1
EMAIL EM1
GOTO LOOP

This will send one email. If you are afraid that email is missed, you can also add a lamp through a relay board. Connects the relay board input to the TTL output 1, then put this program there:

START
SET RAM1 0
LOOP:
TSTGE IP1 1
GOTO SEND
SET RAM1 0
SET OP1 0
GOTO LOOP
END
SEND:
BNZ RAM1 LOOP
SET RAM1 1
EMAIL EM1
SET OP1 1
GOTO LOOP

In this program RAM1 is used as a flag to prevent constantly sending emails.
Please let us know if this helps.

CAI Support
Sorry for the code is little hard to read, since I don't know how to enter space or tab into the forum.

 

[swaggy]

Thanks! I will try this as soon as I can find a spare 5V supply.

 

[swaggy]

I just realized that I have the 12V version of the sensor and according to Webcontrol manual, the maximum supported on the digital input is 5VDC. So sounds like I need to get the 5V version of the sensor?

 

[apostolakisl]

You could also use a pressure tranducer like this http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=MPXV5010GC7U-ND

Seal one end of a pvc pipe and mount the transducer at that end with the nipple connected to the outside. Stick the pipe a couple feet down the hole with the open top end of the pipe well above water level. Connect its output to an analog input on the cai and use the cai 5v out to supply it power. 1 psi is 2.3 feet of water. You can write plc code to do what you like with the readings but it will give you a continuously scaled reading in the range of about 0 to 4 feet of water. Total cost might be $20 for the transducer and pvc pipe.

 

[CAI_Support]

According to this spec sheet:
http://www.grisk.com/specialty/pdf/2600%20Series.pdf

There are four wires for conneciton, red/black and green/white. Red/black is for 12V power souce. Green/White are relay contacts that not connected to the power. However, for simplicity, you can use both side with +12V and have the output connected to analog input of WebControl, which is over-voltage protected, or you can add resistors to divide the 12V with a 10K and 5K resistor, so that feed the 4V to the TTL input.

Make sure use a meter measure it before connecting to the WebControl TTL input, since TTL input and TTL output are not protected, over-voltage will kill the I/O buffer IC.

 

[apostolakisl]

According to this spec sheet:
http://www.grisk.com/specialty/pdf/2600%20Series.pdf

There are four wires for conneciton, red/black and green/white. Red/black is for 12V power souce. Green/White are relay contacts that not connected to the power. However, for simplicity, you can use both side with +12V and have the output connected to analog input of WebControl, which is over-voltage protected, or you can add resistors to divide the 12V with a 10K and 5K resistor, so that feed the 4V to the TTL input.

Make sure use a meter measure it before connecting to the WebControl TTL input, since TTL input and TTL output are not protected, over-voltage will kill the I/O buffer IC.

I own a whole bunch of the the gri 2800's. It is a simple thing that looks like a window contactor. It only has 2 wires that you put dc current across and when it gets wet it conducts. I use it on my alarm system 12vdc security zone and it closes the zone when wet. You could just as easily hook it up to the 5v out on the cai and put the other lead onto a ttl input. The ttl will read 0 when dry and 1 when wet. The 2800 is spec'd for anywhere from 5 to 24vdc. I haven't tested it on my cai, but I have tested the voltage on the cai and it is slightly more than 5v. It says "400ma max" as far as current when wet, but I believe that refers to the maximum amount of current that can be passed through it. I don't think any current will go through (or essentially none) if you don't hook it up to a load (like a relay), but rather hook it up to a ttl input.

 

[Sacarino]

You could just as easily hook it up to the 5v out on the cai and put the other lead onto a ttl input. The ttl will read 0 when dry and 1 when wet.

I tried a similar approach with two garage door reed sensors and found that I had to use a pull-down (or pull-up, depending on how you wire it and configure the board) resistor in order to keep the TTL input from floating and generating false positives.

 

[apostolakisl]

I tried a similar approach with two garage door reed sensors and found that I had to use a pull-down (or pull-up, depending on how you wire it and configure the board) resistor in order to keep the TTL input from floating and generating false positives.

So you're saying you needed to put a resistor between the cai ttl input and the cai ground to keep it at 0 when the circuit is open (the reed switch open so no voltage should have bee going to the input).

In my playing with the cai, I haven't seen any of the unconnected inputs drifting. I did have a problem the first time I wired it up becuase of voltage leakage from wire to wire on the ribbon cable I was using. After rewiring, everything that should have been zero stayed zero regardless of what voltage any of the other inputs were beign given.

 

[swaggy]

Thanks for the reply guys. I think I will try connecting the dry contacts of my 2600 sensor between 5v on the humidity sensor pin on the CAI board (I'm not planning on connecting a Humidity sensor to this board) and the TTL input of the board. The 2600 is normally closed so I think I need to modify the code above to test for a 0 instead of 1 on the TTL input. I will try this as soon as I get the Tyco connector that's needed foe the AUX inputs.

 

[CAI_Support]

Thanks for the reply guys. I think I will try connecting the dry contacts of my 2600 sensor between 5v on the humidity sensor pin on the CAI board (I'm not planning on connecting a Humidity sensor to this board) and the TTL input of the board. The 2600 is normally closed so I think I need to modify the code above to test for a 0 instead of 1 on the TTL input. I will try this as soon as I get the Tyco connector that's needed foe the AUX inputs.

Hi Swaggy,

Humidity sensor is not over voltage protected like analog inputs. Although it is an A/D input, it has logic behind it to calibrated to the honeywell data spec. You may read zero from it. TTL input is also not overvoltage protected. If you applied higher than 5.5V, you could burn the input buffer IC. We had recently customers burned their input or output buffer IC by connected the TTL input to a high voltage, or draw too much current from TTL output. Unfortunately, those is not covered under warranty.

If you are not sure the input level, you can always connect it to analog input to check if the input level is 500 or lower. If it is higher than 500, you may have some risk.

Have fun!

CAI Support

 

[apostolakisl]

As I mentioned, I have the 2800 model which is a normally open contact that closes when wet.

The 2600 as I understand requires 12v power to maintain a relay in the closed position when dry, and when wet it opens the relay. The 12v is independent of the contact closure and is not present on the two signal wires (green/white).

One of the pins on the input section of the cai board is a 5v source (pin 13 of j12 aux input section). Connecting that pin to one lead of the 2600's signal wires (green), and the other lead (white) to the cai ttl input (pin 5) would presenting the cai to its own 5v source. The ttl would read "1" when dry, and "0" when wet.

You would need an entirely separate 12v source for the red/black wires on the 2600.

 

[sic0048]

I'd want to know what the pipe is for! It seems much more likely to allow water into the basement than it will help removing water from the basement.

Do you know where the pipe goes? Do you know what the purpose of the pipe is?

To be honest, I would speak to someone about getting the pipe removed or at least covering it up and patching the hole (if that is OK to do with the original intent of the pipe). Although monitoring the water level is a good idea, if you can prevent the water from entering the house in the first place, that is a better solution IMHO.

 

[swaggy]

Do you know where the pipe goes? Do you know what the purpose of the pipe is?

I think it's for drainage around the house. The pipe would go into a sump well where a sump pump would remove it from the basement. The builder, in his infinite wisdom, decided not to pay the extra $25 to have a sump well installed when they poured concrete. Now I have to cut the concrete to install a well. Either way, I still want to monitor the water level. My brother in law just had his pump go, good thing it wasn't spring.

I never had water in the basement and we had a hard winter (I am in the northeast) so hopefully the pump will not be needed but I feel I should do a proper well anyways.

 

[swaggy]

Hi Swaggy,

Humidity sensor is not over voltage protected like analog inputs. Although it is an A/D input, it has logic behind it to calibrated to the honeywell data spec. You may read zero from it. TTL input is also not overvoltage protected. If you applied higher than 5.5V, you could burn the input buffer IC. We had recently customers burned their input or output buffer IC by connected the TTL input to a high voltage, or draw too much current from TTL output. Unfortunately, those is not covered under warranty.

It sounds like the safe bet is to connect the dry contacts of the sensor between either 12v or 5v and use analog inputs on the board to avoid burning out the IC like you mention.

Thanks