help for interfacing temp sensor to plc unit

hiiiiiiiiii
i am in the final project and need circuit to interface the temp sensor with my plc unit
plz give me your ideas and i will response with quesions
thaaaaaanks my e mail is
[email protected]

ahmedhameed said:

hiiiiiiiiii
i am in the final project and need circuit to interface the temp sensor with my plc unit
plz give me your ideas and i will response with quesions
thaaaaaanks my e mail is
[email protected]

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You will need a temperature probe and a transmitter for your end device and an analog input card for your particular plc. (be sure to match the probe to the transmitter. some are two wire and some are three wire).

The links I provided are the least expensive I've been able to find. If anyone knows where to get them for less, I would very much like to know.

Once everything is connected properly, you will have to scale the analog input to the range of your temperature transmitter. ( see the documentation for your analog input card ).

I really don't know how they compare in price, but I've had good luck using Omega temperature controls.


http://www.omega.com/temperature/tsc.html

If your temperatures are within the useable range and you have several sensors you can get thermocouple (T/C) input cards and RTD input cards for most PLC brands. If yo only have one or two then the T/C or RTD plus transmitter is the most economical.

All of the above assumes you are using a PLC with analog input capability. If not, Omega and GE have signal conditioners that convert the temperature signal from an RTD or T/C into a pulse, with frequency proportional to the input. You can tie these to a high speed counter input on your PLC and with a little math in the ladder logic get a temperature reading.

You should try a device from PRelectronics for the transmiter for RTD/TC. The model number is 4114 and is realatively inexpensive.