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Analog Input Twido
Connect 4 a 20mA to a Twido
By Yesid Hernandez on 24 October, 2006 - 10:47 pm


I have a Twido PLC and a 2 input analog module, I need to connect a siemens sitrans TK-L transmitter to the module. I supposed that because the analog module have a 24V input, it's to supply the sensor, but not sure. Anyone knows about or have you done before? Thanks for your answer.

No, I haven't done it before with these specific brand components, but it's a classic 2 wire loop powered transmitter to an analog input.

According to this press release
the TK-L is a 2 wire RTD temperature transmitter.
2 wire loop powered transmitters require a (nominal) 24Vdc power in its loop.

I couldn't find the instruction sheet for the TK-L on the Siemens site, but a sheet must have come with the transmitter that will show how

24Vdc (+) connects to the TK-L (+);
TK-L (-) connects to Twido AI (+);
Twido AI (-) connects to 24Vdc (-).

The Germans are usually thorough in providing a wiring diagram.

The Twido site makes noises like, "External supply c 24 V external power supply to sensors/preactuators (voltage range 20.4...28.8 V)", (page 28 of the Twido e-catalog for the 2 analog input current card) which I interpret as telling you that you need an external 24Vdc power supply to supply the power to the TK-L transmitter.

Wire up an external power supply.


By Ibraim Yesid Hernandez on 28 October, 2006 - 1:17 am

Yes I did think that way, I have the sheet for the TK-L but just what you said, there is no wiring diagram. I'll give a try the way you said. Thanks.

I having working it, thanks.