Hello,
I am wondering what the best practices are for testing analog 4-20 mA inputs and outputs.
I would like to buy or make a 4-20 mA source to connect to the inputs and watch the changes in the plc program. My question is what voltage should the source be? is 24Vdc too much? What spec on the data sheet for the cards do I look at to verify acceptable input voltages? Based on input range spec I see 10V if I am using the voltage option of the card so is 10Vdc the limit of the 4-20 mA source I am using as well.
For testing 4-20 mA outputs, can I simply disconnect the wires to the output im testing and use my DMM on mA setting to see the values change between 4-20 mA?
If I do not have a meter thats able to measure mA can I disconnect the output wires and use a resistor across the terminals and measure voltage without damaging the card?
How do you guys test analog mA input/output cards and what equipment do you use?
Thanks for your help.
I am wondering what the best practices are for testing analog 4-20 mA inputs and outputs.
I would like to buy or make a 4-20 mA source to connect to the inputs and watch the changes in the plc program. My question is what voltage should the source be? is 24Vdc too much? What spec on the data sheet for the cards do I look at to verify acceptable input voltages? Based on input range spec I see 10V if I am using the voltage option of the card so is 10Vdc the limit of the 4-20 mA source I am using as well.
For testing 4-20 mA outputs, can I simply disconnect the wires to the output im testing and use my DMM on mA setting to see the values change between 4-20 mA?
If I do not have a meter thats able to measure mA can I disconnect the output wires and use a resistor across the terminals and measure voltage without damaging the card?
How do you guys test analog mA input/output cards and what equipment do you use?
Thanks for your help.
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