Assuming that this is a one-off and you just want it to work so you can make some money off it. I would consider using some standard off the shelf industrial hardware - the advantage is that you you don't have to mess with unknown quality hardware.
I'd look for a low cost PLC that has a decent PID control features and an off the shelf Thermocouple module that works well. The Siemens S7-1200 PLC has a very nice PID controller, complete with auto-tune. It is a dream to use for temperature controls. The PID works perfectly. I just did a machine with 10 Temperature PID loops on an extrusion head. Their Thermocouple cards are fairly expensive, but very good. The Automation Direct PLCs have some cheap analog I/O now: http://www.automationdirect.com/adc/Overview/Catalog/Programmable_Controllers/CLICK_Series_PLCs_%28Stackable_Micro_Brick%29/Analog_I-z-O Even if you don't want to use the Automation Direct PLCs (they have no PID instructions, so you need to code your own and there are examples out there ) you might want to buy a $69 PLC and a couple of blocks of I/O and then control the I/O via the PLC's Modbus interface... They have 4 channel 16 bit Thermocouple (TC) cards for $149 with compensation for all of the popular TC types. Very inexpensive considering the competition. Also there are a lot of cheap PID Temperature Controllers that are being imported from China but I have no idea about the quality. http://www.ebay.com/sch/i.html?_trksid=p2050601.m570.l1313.TR5.TRC1.A0.XPID+temperature+control&_nkw=PID+temperature+control&_sacat=0&_from=R40 When it comes to temp control, the hardware is very important and the software is relatively simple in comparison. Dave On 11/8/2013 6:15 PM, Bertho Stultiens wrote: > On 11/08/2013 11:38 PM, Jean-Michel Pouré - GOOZE wrote: >> I need to know to what extend Linux CNC could be used to manage an >> infrared SMT reflow oven. Any ideas are welcome. > That sounds a bit like using a hammer to screw a bolt... > > Sure, you could modify configs and make it work, if maybe not all of it, > but why would you? This application screams for some custom software IMO. > > The easiest thing to do is wire up a micro-controller that reads the > temperatures and can move the caddy, as well as controlling the heating > elements/ventilators. Then you put a serial port on the microcontroller > which you connect to a PC. You could also just do all of this on a > Raspberry Pi as controlling PC and micro-controller if you extend the IO > connector a bit. > > ------------------------------------------------------------------------------ November Webinars for C, C++, Fortran Developers Accelerate application performance with scalable programming models. Explore techniques for threading, error checking, porting, and tuning. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60136231&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
