Hi

I've a problem reading a thermocouple sensor type J with a card as in the subject : AI 4 x RTD 6ES7134-6JD00-0CA1.

The sensor is an ATEX EX type with a simulated output of type J : model Exergen Irt/c.5-280F-140C

I've used the same sensor with ET200S unit and it works perfectly.

The sensor attached to a lab instruments works ok and a standard type J sensor connected to the ET200Sp card works and I can read it in plc.

The problem starts when i connect the sensor to the Et200SP 6ES7134-6JD00-0CA1 card.

I can not see anything on the plc input. 

I can see some mVolt only if I set the input as "voltage " type with 50mV range on plc setup and only if I connect 1 sensor at the time. With 2 sensor connected the reading is zero even on voltage input type.

It seems to me a problem of electronic coupling between sensor and card, like the card It's not able to supply the sensor as the sensor is not a standard joint of 2 materials but is a pyrometer with emulated type J ouput.

Someone know if plc card supply some power to the sensor?

Thanks

Regards

Dave

Hello,

if you can try test and connect other type of sensors like Voltage or Current types. 

Exergen uses a simulated, non-linear thermocouple type output of a proprietary electrical nature,  I suspect is it s thermopile, a group of paralleled T/C's, but that is speculation only.

Exergen's non-contact IR handboo, Exergen IR Handbook ,

mentions that one should avoid analog inputs with a leakage current > 10nA:

"Choose an instrument with a low leakage current (<10 nA).  Leakage current is generated by the circuit diagnostics used to detect t/c wire breaks and by the input amplifier circuit.  Although the measurement offset generated can be calibrated out, choosing a device with low leakage current simplifies sensor installation and calibration." page 10

It's probably worth turning off the break detection circuit for that analog input, if possible.    Check out page 71 (Pdf) for the "Switchable wire break check" for thermocouples.  It switches off the wire break check for the module.

AI manual