1-5V pressure sensors

Hey Guys, I am having problems programming my ML1400. My problem is that I have 6 pressure sensors. they are 1-5v sensors and I have programmed my analog cards and done the configuration on them I believe that it is my input range on my SCP.

does anyone know the range that should get me close to the range i need.

Are you using the base units analog inputs ( only four of them) or an analog card?
If an expansion card what is the complete catalog number of it?

What do you want the 1 to 5 volts to represent in engineering units? If that is what you want of-course.

I am using a ML1400 with 3 ~ 1769sc-IF8U and 1 ~ 1769sc-OF8

I have 1 card working with RTD's which is 4~20ma which is working fine, I have 1 card with VFD CT's which i have not been able to test as they are supplied by the contractor and I have 1 card reading AST DIN43650A pressure sensors which are 1-5V, these are what i am having issues with.

my pressure sensors are reading Suction, Discharge and oil pressure all reading in 0~50 BAR.

Rob735 said:

I am using a ML1400 with 3 ~ 1769sc-IF8U and 1 ~ 1769sc-OF8

Click to expand...

Rob,

The 1769sc-IF8U is a Spectrum Controls universal analog input for the Micrologix 1500 and CompactLogix platforms. Its not compatible with the MicroLogix 1400.

The 1762sc IO family is for the Micrologix.

Would you please clarify, did you mean 1762sc-IF8u or did you mean you are using a Micrologix 1500?

yes sorry my bad it is the 1762sc series i have

Also can you be a little more specific about what "issues" mean.

It would also help us help you if you could post your .RSS file. ( zip it first)

Assuming that you are using the 1762sc-IF8u, and you have configured the module for 1-5V input with raw proportional data format by writing the appropriate bits to the correct O:x.x word then SCP I:x.x 6241 31207 0.0 50.0 F8:0 should properly scale the input.

The manual for the 1762sc-IF8u is at http://www.spectrumcontrols.com/pdfs/abio/0300243-01_D0%28Manual_1762sc-IF8u%29.pdf
On page 3-7 is a table that shows the data format ranges for raw proportional or engineering units.

As Mickey suggested, if you can zip and post your .RSS file we can be a lot more help.

here is the zip file.

Alaric, I am writing to N11 should i be writing to F8 for this instead?

Mickey, Issues I am having are that when I conect me sensors they are not reading anything if I reverse my + - I then get a reading though it is not pressure it floats up and down slightly and when I physically touch the sensor I then get a more drastic floating value. very weird and makes me question my sensors.

I just used F8 as an example. You can choose virtually any word address you want for the destination.

From the program you posted you have not configured your module yet. See Alaric's post for the manual if you don't have it yet.

Rob,

I've had a look at your program and I don't see that you are writing the configuration to the module. You have to tell the module what to do with each channel and you do that by writing to the output word assoicated with the module and channel. So to configure I:3.1 to be enabled and to return a 1-5 volt signal as a raw proportional data with 62 hz filtering you have to write the value 4357 to O:0.1. You can get all of the binary configurations for all of your channels from chapter 3 of the manual I linked to. You also don't have your SCP input min/max set correctly, they should be 6241 and 31207. You can also get that from chapter 3 of that manual.

I suggest you create a subroutine to initialize your modules. Use the first pass bit S:1/15 so that it gets called on the first scan. In that routine you can set up the individual channels for each card a number of ways. You can use a MOV instruction to move the desired hard coded configuration word to each output word. You can use a COP to copy 8 words that you set up somewhere else in memory to the entire output module (my preferred way) or you can use individual OTL instructions to latch each configuration bit on one at a time.

I've attached a quick example file. Its not complete, but it shows you one way to copy configuration words from file N19 to the output words for the 1762sc-IF8u modules. I haven't set the configuration bits in file N19 - refer to the chart in chapter 3 to do that. Change the radix to binary after you open file N19 so you can set individual bits.

Good luck and be sure to let us know how it goes.

Thank you Very much guys the calibration of the "other" cards was throwing me off as I was confussed with input cards configured in the output data file.
Alaric Thank you. I have been told a few times my cards were not configured yet but was still scratching my head as to what I had not done yet. So thank you for the final nudge in the right direction.