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Hi ALL, I need to control the temperature of a furnace. The Thermocouple ouputs are available as RS-485. What Hardware and system configuration should I prefer?

I need to automate the control of a gas carburising furnace. The available signals are Thermocouple K-Type (4 nos., one each from the three zones and one from the geometrical center of the furnace) and Oxygen Analyser. That makes it a total of 5 signals, all available in RS-485 format, which I need to acquire (10 samples/second) and then initiate a control action as per the rule base. Reliability is a major issue and the system has to work in harsh conditions.
What hardware would suit my purpose? I would prefer NI hardware which can be programmed via VB or VC++. LabVIEW may be considered as the last option.
from using the thermocouple/Oxygen analyser signals for controlling it is also desired to store them on a PC for analyses and visualisation (via graphs etc etc)
My need is URGENT and would appreciate any help. Thanx in advance
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You could use a PXI system with RS-485 boards in it. This would allow you to read in the signals and then do your control from within your environment. You can do all of your data analysis and visualization from LabVIEW, CVI, C++, or VB. Up to you on that one. As for the control portion you didn't mention what type of signal would be sent back out based on the input but if it is just analog or digital signals you could use an E-Series DAQ board.

Hope it helps!!
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You may also want to call into National Instruments and talk to a Inside Sales Rep. or a local Sales person in your area.
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Hi Gurudas ,
Typically In gas carburizing, steel is heated above the austenitizing temperature in a gaseous atmosphere capable of providing carbon to the surface of the part. If the atmosphere's carbon potential is higher than that of the steel, carbon from the atmosphere will diffuse into the steel, developing a carbon-rich case of higher hardenability than the base metal .

The whole process go through the process of heat treating from the entrance to the exit covering the degreasing, preheating, carburizing, diffusion, cooling, hardening, post-washing and tempering

For applications like these where you need precise control of your temperature and also acquire signals from oxygen probes the solutions can be confined to two platforms from National Instruments
2) FieldPoint RT
Some of the signals like the t/c would need signal conditioning and so a combination chassis on PXI with suitable signalconditioners ona Realtime Controller would give maximum determinism to your application
trnsforming to maximum reliability , accuracy of the control that you need to do .
The RealTime (RT) Environment has a Host Computer where you can load LabVIEW RT and through Ethernet download the application to a Target environment like PXI or Fieldpoint , where the controller has a RTOS which runs the LabVIEw code .
Once you download the application , the PXI system runs independently intelligently even if the communication between the host desktop computer is lost .
The advantage that you get is that you have a open platfrom like PXI , where you can control the technology .

Gurudas, if you need more information on the system configuration and want to know more about this RT system , talk to me at ranjit_nambiar@hotmail.com or

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