amplifier EBR 40

Somebody works with EBR 40 amplifier it is amplifier a signal of a encoder, namely the signal of a encoder amplifer in a signal square wave of 5v my question is it?

I test several amplifer EBR 40 and i dont have the signal square wave in the output but in the input yes, i see the signal of encoder, so i think the amplifier is it locked or blocked how i can unlocked?, or somebody give me a tip o other way for getting the square wave for what i can read the signal in the card, i have the card 6ES7 138-4DA04-0AB0 in the plc S7-400 and the input is it a wave generator (airpax.

Thanks for your help.

VA is supply for 7805 voltage regulator.
so, it must be more than 5V(about 9~24V)

Vp is count card power supply that is 5V.

Don't connect to 5V0 which is test point.
If the VA is correct voltage.
You can measure 5V0 that equates 5V.(7805 output)