rtd configuration

Hi,


I have probelem configuring the Allen Bradley RTD (1756-IR61)Modules.

Sensor type t100
Sensore mesuirng Range :0-150 Degree centigrade.
Input range is not known for this sensor.

In the configuration window i need to enter the follwoing data.

Sensor type (pt100 )
Engineering High:150 Degree centi
Engineering Low Degree centi
Input signal High : --
Input signal Low :--

I am not sure the range of input signal i should use here for correct configuration of modules.
As per the manual it says to Inpt minimum range is 1 ohm and High range is 487Ohm for pt 100 sensor type with range -200 to 870 Degree centigrade.


What input range should i use here for proper temp mesurement.

With Regards
SCAN.PLC

I guess everyone does it differently on how they scale the modules. I personally have engineering max and min in my program, which i use to limit the values. Since the value you are reading from the module are the physical temperatures (implying in degF or degC), i would just leave the scaling as it is, and in the logic deal with your scaling.

You could cause an alarm say if it exceeds your max of 150F. Again as i mentioned everyone has their own way of doing things.

If you really do want to scale it in the module config,

High Signal = 150
Low Signal = 0
High Engineering = 150
Low Engineering = 0

Hope that answers your question.

Hi,

value you are reading from the module are the physical temperatures (implying in degF or degC), i would just leave the scaling as it is, and in the logic deal with your scaling.
As per the manual for RTD modules the High and low signal is not the measured temperature .It is the input signal range (in Ohms) for RTD module (like 4-20mA input range for miiliamp input modules).

My engineering high and low are 0-150 deg.
But i am not sure what input signal corrosponds to this range.

I just leave it at the default 1 - 487 f and I do not have any issues with scaling. The actual temperature updates correctly.