Trends

[Moran]

hello,

 

i need to measure a sin signal 40MHz freq and 3V.

i wand to show this signal on the PLC screen and i need the PLC to monitor this signal and in case of the signal disappear to print a FAIL massage.

 

1. can i measure this frequency?

2. should i use trends?

 

i am using the V570 PLC.

 

some help will be appreciated.

 

thanks.

[Joe Tauser]

No, the PLC can't see a 40 MHz 3V signal.  The highest frequency we can see is 20 kHz and the amplitude needs to be at least 17 volts.

 

You're going to need to roll your own circuit - I would start with something like this-

http://www.linear.com/product/LT5538

 

Run the output level signal into an Unitronics analog input.

 

Joe T.