1769-IT6 compact logix

[speaksy87]

hello, im having trouble using the raw data in my program for a temperature. this is the first time ive used the IT6 card
I have 6 thermocouples type J
I want to use each temperature as a reading in rslogix 5000
to set up alarm points ?? I have each channel configured to engineering unit10x
im just unfamiliar with how to extract it into my ladder logic

 

[daba]

The input data tag for each channel is an INT.

When you set the channel for "Engineering units x10", the data you get in the INT tag is the temperature in the chosen units (deg.C or deg.F) with 1 "implied" decimal point.

For example, if the measured temperature is 38.4 deg.C, the input data tag member will have the value 384.

The easiest way to handle this is to DIV all your input data into REAL tags - e.g. DIV Local:1:I.Ch0Data 10.0 Ch0Temperature.

Doing so will mean that you will always be using proper, unscaled, engineering units throughout your control code, which is a huge bonus for maintenance and troubleshooting.

 

[speaksy87]

Thank you very much

I Found I also had to Multiply each INT value by .1 to get the value to display each value as a decimal

 

[daba]

I Found I also had to Multiply each INT value by .1 to get the value to display each value as a decimal

Isn't DIV by 10.0 the same as MUL by 0.1

 

[Passman]

I use scp to a tag.

 

[daba]

I use scp to a tag.

SCP is overkill when the data in the input tag is just a x10 factor of what is needed.

Agreed it will work admirably, but a DIV or MUL would execute faster...