Host Engineering Forum
General Category => Do-more CPUs and Do-more Designer Software => Topic started by: Garyhlucas on March 30, 2018, 12:39:44 PM
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I was looking to buy one of these modules and I see they are not available. Any idea when this situation changes?
We use Dissolved Oxygen, pH, and ORP probes in our waste treatment plants. The instrumentation cost for our 10,000 gpd plant is essentially the same as for a 1,000,000 gpd plant! Currently that is about 5% of our total plant cost so we are always looking to reduce that cost. One vendor discontinued the transmitter connected to the DO probe, on the very first job! So now I may have to find a new vendor for both parts.
I am seeing now that all three probes we use actually put out a millivolt signal, which the connected transmitters convert to 4-20ma for the PLC. I am thinking to take the millivolt signals directly from the probes using the BX-04THM and do the scaling, conversions and such directly in our PLC and eliminate the cost of those transmitters. Then we essentially don't care whose probes we are using, we can calibrate for those probes and move on.
I am thinking this is really possible because for instance I don't need DO over a range of 0-20mg/L typical. I only need to maintain a target somewhere around 1 mg/L and even a simple calibration using a lookup table and interpolation would be good enough. For pH I need to hold 7.5, for ORP its millivolts directly in a range of -200 to +200 and it is used only as an indicator not as a control point.
Anyone have thoughts on this?
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I was looking to buy one of these (BX-04THM) modules and I see they are not available. Any idea when this situation changes?
Host manufactures the BRX MPUs and the Discrete I/O modules. The BRX Analog Modules are supplied by FACTs Engineering to Automation Direct. Hence, we don't know either. :-[
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It's a startup initialization issue, probably just firmware. I expect a fairly quick resolution, but we don't have direct control or visibility into the problem and remedy.
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Interesting, because the FACTS thermocouple signal conditioners are shown as out of stock too.
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Interesting, because the FACTS thermocouple signal conditioners are shown as out of stock too.
You could use the universal signal conditioner, though those are a bit more pricey.