TC 125 LED

[MYWONG]

Dear All,

I am programming a TC 125 field point module, but its Channel LED is always off whether does i connect any TC, does anyone know why?

I know it is supported to be red if no TC connected and off if TC connected...

any ideas? thaks!

[MYWONG]

of course, i have set the range already...(-270 to 1770) celsius

[Ching_F.]

Hi MYWONG,

Below is a section of the cFP-TC-125 Operating Instructions that describes when the red LEDs will be lit.

"When the module detects a signal outside a configured temperature range on a channel, the red LED for that channel lights. Signals outside the configured range include those that indicate open thermocouples.  The red LEDs do not light in response to out-of-range signals on channels configured for the –20 to 80 mV range."

You can find the cFP-TC-125 Operating Instructions here.

[MYWONG]

Yes, i didn't connect any TC to the TC-125 and already set the range to -270-17xx celcius ( Not in voltage range), but the LED still turn off ? Even i connect a TC to the socket, the reading always show me -270c,

But i replace any other TC-125, it works normal.
1. LED turn Red, when no TC connected

2. LED turn off, when TC connected, and the reading is around 25c , which shows correct temperature reading.

So , i really suspect that the hardware (TC-125) got something wrong, but i am not sure.

[reggier]

Hi MYWONG,

I think you are probably correct, it is probably a broken module.  I suggest calling us here at NI to try a couple troubleshooting techniques and if that doesn't work, set you up to return the TC 125.

Reggie Rector ¦ Applications Engineer ¦ National Instruments