on off Tempurature control with hysteresis

[satriany]

Hello Everybody,
i'm about to controll the temperature of a  heater between two values upper limt an lower limit  i finished the VI  to measure  the  actual value and  also  to switch on and switch off the realy which is connected to the heater. i need to produce   hysteresis in which i can compare my real value with the upper limit and lower limit  and get the output signal only when the actuall value between these two values.
i want to ask if there is special VI which makes this funktion dierctly
i have labview version 7.1
and PXI 4351
thank you very much

[devchander]

Are you using DIO lines onboard 4351 for switching on/off heater??

If u are, just acquire value, use a 'in range?' function from comparisons tools>.functions palette for checking for hi gh and low limit.

Connect the boolean output of this function to a case structure and perform high/Low Digital output on DIO lines inside appropriate case.

Hope this helps

regards

Dev

[satriany]

Hello devchander,
Thank you for replaying
no i use  NI PXI 2565 general  purpose relay switch to switch on/off the heater and i produced the required DAQmax which control this relay as a digital output signal
i use the PXI 4351 only to measure the temperature

do you have any suggestions
thank you
Satriany

[devchander]

Yes my suggestion is use the same programming logic I have explained in previous post.

Just put the code for switching on/of relays on PXI 2565 inside the appropriate case