Internet PLC Forum

General => Technical support => Topic started by: slabit on October 22, 2004, 01:34:35 AM

Title: E10-npn Inputs
Post by: slabit on October 22, 2004, 01:34:35 AM

The hardware specs say the the input can be pulled low with either open circuit or 8.5v to 24v, and high at 0V to 3.5V DC. My question is, will the input stay low with 12volt DC applied to it? I'm needing to sense if a 12volt pump is on or off, and it looks like I can directly connect the input to pump positive terminal. Would this give me logic 0 with 12V applied (pump running) and logic 1 with open circuit (pump off) (the logic I need), or would it be better to just use a relay with contacts switching to ground?

Title: Re:E10-npn Inputs
Post by: support on October 22, 2004, 11:53:50 AM

If you apply a +12V to the input it will be taken as "OFF" to the CPU. Only if the input is pulled below 3.5V (best if it is below 2.5V) will the input be considered to be "ON" by the CPU.