Confirmation of the steps to deal with Flow Measurement- Instantaneous and Totalized | S7-1200

I am new to the automation world, so pardon me for asking the questions that may seem mundane. I haven't worked on analog values before so I would really appreciate your valuable inputs on the project that I am working on.

So for my current project, I need to deal with the Flow rate that is coming from the Flow Transmitter in the field to my S7-1200 PLC in the form of 4-20mA. I need to control the logic of the program with the Instantaneous value of the Flow rate and I need to display the Totalized Flow rate. So after going through various articles, I thought the following steps would be appropriate to accomplish my task. It would be great if anyone could confirm the following steps:

1. Say the 4-20mA input is connected to %IW68. First I need to Normalize it using NORM_X Block (Int to Real) between 0 and 27648. Then I need to scale that result using SCALE_X (Real to Real) between say, 0 and 10 Feet Per Second (FPS). Now let's suppose I store the result in %MD80. This is the Instantaneous Flow Rate. I can now use the value in this register to control the logic of the program.

2. For Totalized flow rate, I understand there are many methods such as using theTotalized Blockand by usingNumerical Integration. The approximate totalization would do, and the accurate totalization by using pulsed inputs is not needed in this case. So out of all these methods, I think using the Totalized Block method as described by the Siemens Support (given in the above link) would work just fine.

3. In the sample program that they have attached with that link, can I incorporate that entire sample program to my main program by changing few parameters accordingly to achieve Totalized Flow for my project? The parameters that I would like to change in the Sample Program while incorporating it into the main program are inside the Totalized Block in the Cyclic Interrupt [OB200] as follows:

Value: %MD80 (Our instantaneous Flow Rate)

Intervall: T#1s (Flow is in Feet per Second)

Cycle: T#100MS

Reset: %M1.0 (First Cycle)

Output: %MD30

Rest everything in the Totalizer_1 [FB60] and Totalizer_DB [DB60] as well as the Tag List would remain as it is, according to my understanding.

Hence in the end, %MD30 would have Totalized Flow Rate.

As I do not have any hardware with me to test on, I would really appreciate if anyone can verify the logic of the above steps.

Thank you once again.

Best Regards,

Parshva

Thank you for the reply. I indeed hope someone can help me verify these steps.

Best Regards,

Parshva

Thank you very much for the reply. I would like to try out the method using the souce code from OSCAT, but I'm afraid I don't know anything about SCL. I am only comfortable using LD (and a bit of FB). Moreover, the Totalizer Function Sample Program would work out in the manner that I intended. I at least think so. Let me try that out first. If it doesn't, I'll hope to consult you again in this thread.

Thanks again.

Best Regards,

Parshva