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PLC analog comparators
- Thread starter sanderscj
- Start date
Sanderscj,
The input signal to the plc needs to be converted (obvious statement i know) the 0-9.9v sounds a bit unusual to me. I suggest if you have 24v dc available at the application, contact your local instrument and process control company ( look for one flogging thermocouples in thier ads. They can sell you a "2 wire hockey puck " unit which will give you 4- 20 ma . Run this through your plc input ( IF IT IS ISOLATED ) with a precision 500ohm resistor (ie < 1%) hooked in parellel across the input terminals.
If the unit is not an isolated input talk to the instrument company they will have a suitable signal converter. The PLC manufacturer may have an input card to suit.
What brand is the plc. You will not get a reading from the A/I terminals for a thermocouple. What temps are you measuring NEC have a chip thats good to about 50C.
Let us know how you go.
regards Don
The input signal to the plc needs to be converted (obvious statement i know) the 0-9.9v sounds a bit unusual to me. I suggest if you have 24v dc available at the application, contact your local instrument and process control company ( look for one flogging thermocouples in thier ads. They can sell you a "2 wire hockey puck " unit which will give you 4- 20 ma . Run this through your plc input ( IF IT IS ISOLATED ) with a precision 500ohm resistor (ie < 1%) hooked in parellel across the input terminals.
If the unit is not an isolated input talk to the instrument company they will have a suitable signal converter. The PLC manufacturer may have an input card to suit.
What brand is the plc. You will not get a reading from the A/I terminals for a thermocouple. What temps are you measuring NEC have a chip thats good to about 50C.
Let us know how you go.
regards Don
jbartos
Electrical
- Jan 15, 2000
- 6,440
Suggestion: Generically, a voltage amplifier is meant to amplify the voltage. Check manufacturer products over
for a possible thermocouple - plc finetuned set.
for a possible thermocouple - plc finetuned set.
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