newbie question pls help

[aryan_iust]

Thanks Lancie. I got my answer.
There in so internal register or alarm which I can use directly.
I will probably use a voltage converter to convert the voltage to 10V DC max and read the value from the on-board analogue input on the PLC.
BTW, my PLC is L32BXB which requires 24V power supply.

 

[Lancie1]

Yes, you need something like the Omega CCT-01-0/650V signal conditioner (transducer). It has a 0-650 DC input, and 0-10 volt DC output, for $180.
http://www.omega.com/pptst/CCT.html

 

[Lancie1]

You should set your alarm to go off at about 21 volts. When the voltage drops to 20 volts DC, your MicroLogix 1400 will go offline. The voltage spec for the ML 1400 1766-L32BXB is 24 VDC (-15%, +10%), meaning your acceptable range is 20.4 to 26.4 VDC. If you have an adjustable supply, you could set it to 25 VDC, allowing you to set the alarm at 22 volts, giving you a few extra seconds to sound the alarm before you lose the ML on a dropping voltage.

Or you could use a UPS.