Totalizing liters per minute with ab slc 5/03

J

Thread Starter

Jimmy Fletcher

I am currently having a problem with excessive chemical use unaccounted for. I want to make a totalizer to meter the chemical as it is being filled into the tank. I am using a rosemount 8732c magnetic flow meter with a 4-20 ma output and a frequency output. I want to display the total chemical usage on the panelview preferably using the 4-20 ma output on the flowmeter. Could someone please send me some code to get me started in the right direction?
 
D
I have just written a solution to this in Siemens S7 300, as I have to totalise a component into a mix. I could either send you the program block by email (to view you will have to use Siemens Step7 software) or fax you a printout.
 
I have done this many times but I don't have the exact code handy right now. All you have to do is generate a pulse at a fixed interval I do it every six seconds with a timer and its normally closed done bit in series with it. When this timer is done add 1/10th of the LPM input to a total floating point variable and make the result the same variable (total = 1/10 flow + total every six seconds). To clear the totalizer just zero the totalizer floating point from the HMI or with a clr instruction. If you need a better example email me [email protected]
 
I have done this many times but I don't have the exact code handy right now. All you have to do is generate a pulse at a fixed interval I do it every
six seconds with a timer and its normally closed done bit in series with it. When this timer is done add 1/10th of the LPM input to a total
floating point variable and make the result the same variable (total = 1/10 flow + total every six seconds). To clear the totalizer just zero
the totalizer floating point from the HMI or with a clr instruction. If you need a better example email me [email protected]
 
B
The 4-20mA will give you instantaneous flow rate which you can average/totalize as suggested.

The frequency output will give a pulse every time a known volume flows (the pulse rate or K factor should be on the flowmeter). You could simply use a counter to record/display the total useage.

 
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Eduardo Manuel C. Cipriano

Hi I have been with AB for 4 years as a Sr. Automation Engr. for Tech Support

what you could do is you have two options

you could make a scale parameter program at the SLC 503 to compute and totalize your chemical consumption

or

you could use the capability of your Panelview to compute in terms of expressions that is bulit in in your Panelview so this is a better way because you dont have to add any additional program in the PLC and this lessen the execution time of your PLC because Panelview Itself can do calculations....

anyway if you have additonal questions you can email me at:

[email protected]

Eduardo Manuel C. Cipriano
Sr. Systems Engr.
Yokogawa Phils. Inc.

> I am currently having a problem with excessive chemical use unaccounted for. I want to make a totalizer to meter the chemical as it is being filled into the tank. I am using a rosemount 8732c magnetic flow meter with a 4-20 ma output and a frequency output. I want to display the total chemical usage on the panelview preferably using the 4-20 ma output on the flowmeter. Could someone please send me some code to get me started in the right direction?
>

 
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