pt100 signal goes open in mirologix 1400

hello friends
i have installed a system for the wax feed
in which i have to control the temperature for this purpose i used pt00 for temperature ranges 16 to 204 degree c
i have used a module 1762-ir4
but problem is signal from the pt100 does come to module also come to the plc but after some time it shows 8500 if i changed to downscale then it shows -2000 means it goes open the signal i have used ssr for the heating purpose
i have used scale 0-4095 and 16-204 temperature
can any one tell me what is going there ?

It is very likely that the conductors for the RTD sensor are becoming an open circuit and the module is correctly indicating that status.

From page 1-7 of the User Manual (Publication 1762-UM003):

Each time the module reads an input channel, it tests the data for a
fault (over- or under-range, short-circuit, or open-circuit condition). If
it detects a fault, the module sets a unique bit in the channel status
word.

Click to expand...

Do any of the status bits in the Input data table indicate an open-circuit ? These are illustrated on page 3-3 of that same User Manual.

How is the condition repaired: does the system cool down, or do you cycle power, or something else ?

it does not use scale.
only connect the rtd to the module and set the module to the approriate sensortype (jpt100)