Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: bdrotaru on November 16, 2011, 10:14:33 AM

Title: CAPAITIVE THC PLASMA PROBLEM
Post by: bdrotaru on November 16, 2011, 10:14:33 AM

I have a problem with inputs to Mach3.
I have a height sensor (THC) in a plasma cutting machine that emits four signals:

Torch UP
Torch Down
Torch ON (given by a capacitive sensor which considers optimal cutting distance)
Probe (Touching the board)

Now ... Depending on the condition that the z axis is found to give an appropriate signal pin MACH3 attributed to the state and activity is 15VDC and inactive is approximately 3.2 VDC at about 100mA

The downside is that  MACH don't read input state even though I tried both direct connection to the parallel port and breakout board.

Initially I thought that my parrallel port is broken but I checked the input port of MACH3 with Autodetect Inputs and both directly and through BOB works very well.
Can anyone tell me as to why I do not see the signal from the THC MACH3?

Sorry for my bad English
Thanks

Title: Re: CAPAITIVE THC PLASMA PROBLEM
Post by: rrc1962 on November 16, 2011, 07:17:32 PM

Sounds like you need to build an interface between your THC electronics and Mach3.  The parallel port is not compatible with the 15VDC signal coming from your THC.  Most breakout board will not be either. 

Title: Re: CAPAITIVE THC PLASMA PROBLEM
Post by: bdrotaru on November 20, 2011, 08:17:49 AM

I built an relay interface but sadly the relay are not fast enough. Can someone help me with this problem?

Title: Re: CAPAITIVE THC PLASMA PROBLEM
Post by: rrc1962 on November 20, 2011, 11:13:30 AM

Maybe use transistors instead of mechanical relays. 

Title: Re: CAPAITIVE THC PLASMA PROBLEM
Post by: BR549 on November 20, 2011, 11:38:23 AM

Do you have a manual for the THC????

(;-) TP

Title: Re: CAPAITIVE THC PLASMA PROBLEM
Post by: rrc1962 on November 21, 2011, 02:54:27 PM

Is it this one?  This is supposed to work with Mach3, and it's not terribly expensive.

http://www.agelkom.com.tr/mach3.htm

Title: Re: CAPAITIVE THC PLASMA PROBLEM
Post by: bdrotaru on November 21, 2011, 03:00:40 PM

yes. the exact one

Title: Re: CAPAITIVE THC PLASMA PROBLEM
Post by: rrc1962 on November 21, 2011, 03:28:53 PM

Did you contact the guy you bought it from?  It's supposed to work with the Mach3 THC Up and Down inputs, which means you shouldn't be seeing 15VDC on any of the THC outputs.

Title: Re: CAPAITIVE THC PLASMA PROBLEM
Post by: KTM on November 26, 2011, 12:56:51 AM

The Cap. THC has a very low current PWM output which is made for the H-Bridge to drive a DC motor more accurately.
I preferred the old THC which only had digital up/down signals.
 I suggest you speak to Argun for a solution, or if it is possible to send the THC back, order the older version.

Regards

Steve