View Single Post
  #1   Spotlight this post!  
Unread 20-02-2012, 00:27
maddoctor90's Avatar
maddoctor90 maddoctor90 is offline
Registered User
AKA: Matt
FRC #2481 (Roboteers)
Team Role: Mentor
 
Join Date: Feb 2008
Rookie Year: 2007
Location: Tremont
Posts: 79
maddoctor90 is a splendid one to beholdmaddoctor90 is a splendid one to beholdmaddoctor90 is a splendid one to beholdmaddoctor90 is a splendid one to beholdmaddoctor90 is a splendid one to beholdmaddoctor90 is a splendid one to beholdmaddoctor90 is a splendid one to behold
Re: PNP Inductive Sensor

You can run an external circuit to power the 12V sensor and not use the digital sidecar power. You will then need to attach a pull down resistor between the signal going into the sidecar and ground. See the pull down resister configuration in http://en.wikipedia.org/wiki/Pull-up_resistor for more information on what I am talking about. The sidecar is simply an IO interface to the 9403 module. Thus the data sheet here http://www.ni.com/pdf/manuals/374069e.pdf will tell you that you the module is protected for up to +- 30 Volts. The AB photo sensors (npn) available from FIRST Choice will feed 12 volts signal into the digital sidecar and I have not heard of any teams having any problems with them, so I think you will be fine feeding a 12V signal to your digital sidecar. In fact, we are currently using a 12 volt PNP prox using the configuration I just described. I would like to comment though, if you use a 12V sensor and your battery voltage drops below 12V, the sensor will turn off. Also, you need to make sure not to have your pull down resistor (a custom circuit) off of the same breaker powering the sensor, as this would be a violation of R47.