8AI/0 for M91-2-T38

[Srle]

I have a temperature measurement  (4 mA) -200 °C til (20 mA) 50 °C . 

The mesurement needs to show on the LCD Dispaly and to bee sent via SMS.

I used linearization Display values X=-200 and Y=50 for MI- value 3277 to 16383. 

I works only when X is grater then 0 (Zero). Any suggestions?

Thank you 

[Flex727]

It's easy to set up the linearization wrong. Post your code.

[Joe Tauser]

Don't use linearization display functionality.  You can't access the linearized value anywhere else.

If you're going to be embedding the temperature in an SMS message then you need to use the special function blocks in ladder to put the linearized value in an MI.  You can put this on the display, too.

On 12/21/2017 at 6:46 AM, Flex727 said:

Post your code.

+1

Joe T.

[SaaHar]

On 12/24/2017 at 1:40 AM, Joe Tauser said:

Don't use linearization display functionality.  You can't access the linearized value anywhere else.

If you're going to be embedding the temperature in an SMS message then you need to use the special function blocks in ladder to put the linearized value in an MI.  You can put this on the display, too.

+1

Joe T.

If the only requirement is to send the value in an SMS, the display variables are the preferred way, since you need to set one up regardless for the SMS. If your intention is to use the linearized value anywhere else, try placing your measured low value in SI 80, your measured high value in SI 81, your adjusted low value in SI 82 and adjusted high value in SI 83. Then place your measured value in SI 84 and call SB80. The linearized value will be placed in SI 85. Attached is an example piece of code (in a little different order, but works), which i use to measure pressure from 0 to 11Bar using 0-10V analog input.

PressureLinear.U9N

[Joe Tauser]

You're supposed to call SB 80 last (in a separate net) after you've loaded SI 80 .. 84.  If you're variable isn't changing fast your code will work fine, it's just kind of backwards.

Joe T.

[SaaHar]

4 hours ago, Joe Tauser said:

You're supposed to call SB 80 last (in a separate net) after you've loaded SI 80 .. 84.  If you're variable isn't changing fast your code will work fine, it's just kind of backwards.

Joe T.

which is true, and this should be followed. In my case sb 80 is set every 3 seconds with a timer  (which is not shown in example) and just had to plonk it in there to complete the example. This works aswell, but you should follow the worded quide, and as Joe T. said, set the SB 80 AFTER you have set the variables in the SI's