E+H 83F Frequency output to a 1756-CFM

Hi guys,

Im trying to make this flowmeter work properly, (Endress+Hauser Promass 83F) i did some batch test to weight my liquid and the totalizer on the promass is prety acturate. its prety much the same weight than the Promass totalizer is reading.

Im using a Metering card 1756-CFM for my contrologix for this flowmeter (input #8 F0 and #10 F0 RET)

On my panelview when i want for exemple, 1000kg i put it in my Target, and when my total reach 1000kg and compare it with my flowmeter totalizer my HMI total is prety much always 4 times higher than the one on my flowmeter...
So if i target 1000kg.... my total on my HMI is 1000kg and my Flowmeter is 250kg

if i put 2000kg for target, the total on my HMI is 2000kg and my flowmeter is 500kg.

We are using a Frequency Output for the mesurement of that promass 83F (Connection #24 and #25)

When im watching my value in logix 5000 it seem that the 2 value im reading is the Netvolume and the Netrate.

I did some simulation test but it look like im not always getting a value, im starting to wonder if my cable and signal is good.... if i get a pulse every 4 pulse or something because my cable is bad it one of the problem im thinking ...


anyway i linked a PDF of my ladder if any of you could look and tell me what test should i try to find my problem or something.


in the Promass83F in the Freq output setting it was:

Standard, passive Positive, Fallback Value, and i should pulse every 2.2046lb.... (1.0 kg)
the min hx is 2.0 and max is 1250hz

Are you using a Frequency output or a Pulse output? There is a big difference between them. If you want to measure a actual amount then you should be using a pulse output.

I have never used this module but looking at the manual it looks like it is looking for a K-Factor which is the pulse per unit of measurement. So pulses per LBS or gallon or whatever the meter measures. So I would not use the frequency. You will set up the the pulse output as X number of LBS per Pulse. So for 10 pulses per Lb you would use a .1 in the meter and 10 for your K-Factor in the module.

Well im prety sure im using it in pulsing. My Promass can do both Freq output and pulsing. I tested both.

In pulsing mode i setted my promass with these setting:

Pulse
Mass Flow
100ms ... (put my Metering card also at 100ms)
in passive positive

and in simulation mode pulsed 25 times, after that 50 times and 100 times

After 25 pulse simulated i could read 9.6kg in my FT_0012.PV
After 50 pulse simulated i could read 18,3kg in my FT_0012.PV
After 100 pulse simulated i could read 36,6kg in my FT_0012.PV

Just like if my pulse was * by 0.366 somewhere. maybe my k-factor is bad in my Promass

I guess tomorrow im gonna try using this function i found in the PDF of that metering card 1756-CFM
I.Status[0].TotalCounts

If i get the same count there than the # i simulated in the promass i guess my pulse are working properly and its only a matter of conversion

What do you have the output K-Factor in the meter set to? Also make sure the 100ms the proper pulse width for the Mass Flow Rate you have. We normally have our Promass set up to 10,000 pulses per Barrel of Crude Oil. The pulse width we normally use is .1 or .05ms. Our K-Factor is .0001BBL/Pulse. Remember the Promass does its K-Factor differently than normal. It is expressed as Units/Pulse as opposed to Pulses/Unit like most K-Factors are expressed.

Also make sure you have the Meter Factor in the card set to 1.0000. I haven't looked at this card enough to be fluent in it but most "Flow Computer" devices will show gross volume using this equation: Total pulses/K-Factor X Meter Factor = Gross Volume. So if you have a .366 in the meter factor you will get the results you showed.

I did more test today, i know now what my total in KG on my HMI is the Netvolume of my promass.

with the setting i got 1 pulse is 9.16 netvolume on my HMI
If i want to change them i know which setting to play with.
Now i know that
Netvolume = Total Pulse/K-Factor*Meter Factor*CCF
So in my program... 1/1.0*1.4971*6.12 = 9.16 which is exactly the KG i get on my HMI every pulse i do

I did few test with the pulse simulation of that promass and after 100 pulse test in my Totalcount status i had only like 5-6 pulse.

my 1756-CFM is set at 100ms RPI and my promass at 100ms pulse width. My cable is also shielded and connected to 1 side only.

im in Passive Positive pulse.

The best i could do is try a new cable, i dont have a oscillator or anything to watch closer my pulse, i guess im going to call some tech support on this one to help me out

I may be wrong here, but I believe the promas has a setting for scale for display that is independent of the scale for output(s). Have you checked that the scale is the same for both? Again, not sure, we normally just use the 4-20 options and let the PLC do the calc on totalizators.

same here... everything here is on a 4-20ma or simply a relay output pulsing and modbus for 1-2 application, from what a hear my boss bought the promass without knowing anything about the communication and they were kinda stock using it...

If you have the Promass set up for Passive Positive then the power for the pulse has to come from a separate source than the meter. Are you sure you have it wired up properly for this? I normally use Active Positive for my pulse setting.

Bullzi said:

If you have the Promass set up for Passive Positive then the power for the pulse has to come from a separate source than the meter. Are you sure you have it wired up properly for this? I normally use Active Positive for my pulse setting.

Click to expand...

I need to confirm it, but im prety sure my 1756-CFM is my source of power for my pulse,

im using F0 Channel and F0 Return of this 1756-CFM card which is normaly used for flowmeter purpose.

Finally, we make it work

I don't know whos the guy that worked on it before us but damn all the parameter he could play with he did.

We found on the PDF of thew 1756-CFM card it was a sinking card only so it have to choice the pulse have to come from my promass, so the first thing we did is put it in Active and not passive positive....

And we prety much put every setting back to the default value like the k-factor, combined, meter sample etc


Just to make sure we used a oscillator just to watch the pulsing if they were good

now im receiving all my pulse and my water batch are prety accurate.


Thanks for all the tips also, they were prety useful to solve my problem.