Change of dc supply voltage after connected to analog input module of delta plc

Hello everyone
I got problem during practical.
I am using delta plc modelVP20EX00R2.
Problem is that when i give 7v dc supply through bridge rectifier to analog input of delta plc (A0v+) and (A0v-)..When i check the voltage across (A0v+) and (A0v-) through multimeter...I got 14v...How is that possible that i give 7v from bridge rectifier to analog input of delta plc and 7v convert into 14 v..
Please help!!!

I'm missing something. Why do you need to put your 7 Vdc through a bridge
rectifier?

Is the ground reference for the 7 Vdc the same ground reference at the analog input
module? (Try reading the volts plus to plus, then read the volts minus to minus.)

I can see 7 Vac going through a bridge giving you 14 Vdc. I have a circuit that
powers some DC brake coils. 120 VAC goes into a bridge, and if all the brakes
are turned off I'll read some 240 Vdc. (There are some capacitors involved.)
Poet.

(1)Thanks alot Poet for your response.
Yeah you are correct.
The capacitor was involved in my circuit.And when i removed the capacitor i got 7 Vdc through bridge rectifier..Can you answer me why this was happened that i got 14 Vdc when there was capacitor in my circuit... and then i got 7 Vdc when i removed the capacitor...

(2)
Dear Poet..
I was using capacitor before bridge rectifier and after 220Vac..Then i got the problem of 14Vdc...Afterward removing capacitor
But when i use capacitor after bridge rectifier it provide pure 7 Vdc with some variation in dc voltage...(after 220Vac capacitor not included)
so how i can remove this variation too.
Regards

Make sure I got this right . . .
220 Vac . . hopefully through a transformer to knock it down, then a bridge to make
it 7 Vdc. Then that 7 Vdc goes to an analog input?

Are you trying to get a fixed 7 Vdc input to the module for a reference?

Sounds like your existing 7 Vdc has very little load. So any spikes or variations
to the input power will be 'stored' within the capacitor causing some variation
of the dc volts.

Adding a load resistor to the 7 Vdc might help.

Or, if the 7 Vdc needs to be more precise changing the transformer so you
have a good quality 14 Vdc then add a voltage regulator to get 7 Vdc.

I also think you need someone more related to an electrical engineer than me
to help you out here.
Poet.

Thank you