Twido TMI2AMI4LT for Pt100 help

Hy guys,

Does anyone worked with Twido PLC (TWDLCAA24DRF or TWDLMDA20DTK) and aditional TMI2AMI4LT analog input module?

I need help with these problems :

I have to measure temperature with 2 rtd pt100 sensors...In order to do this i cannot find information it TMI2AMI4LT analogue input module supply the sensors with the constant current source they need or i need an external constant current for sensors.

Also...what will be the difference between a compact module TWDLCAA24DRF or a modular one TWDLMDA20DTK besides input/output count? Wich is better and why?

Hope someone with more experience than me can help me with this problems...

Thanks in advance!
Ionut Capitanu

Search from web: Twido Programmable Controllers Hardware Guide Analog I/O Modules

Page 65 shows, how to connect PT100 sensor. page 65 is on attachment. If I understand it right, analog module only needs power from power supply.


Difference between modular and compact modules is that to compact module you can't add additional modules.

To modular PLC you can add up to 7 different I/O modules.

RTD wiring diagram for TM2AMI4LT module is attached.

TWDLCAA24DRF is compact type but support upto 4 extension modules
and 230 V AC power supply can be directly given to PLC

TWDLMDA20DTK is modular type and support only 4 extension modules simialr to TWDLCAA24DRF. But there is no Power supply module built-in, so 24 V DC supply to be given directly to this PLC.
Bigger Twido PLCs like TWDLMDA40DTK support upto 7 extension modules

TWDLCAA24DRF is little wider than TWDLMDA20DTK and also 10% more expensive

iknowsomeplc said:

RTD wiring diagram for TM2AMI4LT module is attached.

TWDLCAA24DRF is compact type but support upto 4 extension modules
and 230 V AC power supply can be directly given to PLC

TWDLMDA20DTK is modular type and support only 4 extension modules simialr to TWDLCAA24DRF. But there is no Power supply module built-in, so 24 V DC supply to be given directly to this PLC.
Bigger Twido PLCs like TWDLMDA40DTK support upto 7 extension modules

TWDLCAA24DRF is little wider than TWDLMDA20DTK and also 10% more expensive

Click to expand...

I saw already the rtd wiring for TMI2AMI4L with RTD configuration...but i'm not sure that it doesn't need an external current for those RTD's...i think that maybe if it is like this in those diagrams it means that no external current source is needed..

I don't have a lot of experience and i didn't want to fall in a "trap" and place an order...and after that to see that it will not work..

I see now the diference between modular and compact one...
a compact one can get 240VAC power supply but with the modular i need an external 24VDC power supply..

Thanks for your replies!

My mistake, I writed from memory and I didn't checked if I remember it right.
Some compact base PLC don't support extension modules at all.


TWD LCAA240DRF (Compact), 230VAC, Screw terminal block, max. 4 extensions modules

TWD LMDA20DTK (Modular), 24VDC, MIL connectors, max. 4 extension modules. (Check, if you need to order mil connectors separately for this PLC)

Lare said:

My mistake, I writed from memory and I didn't checked if I remember it right.
Some compact base PLC don't support extension modules at all.


TWD LCAA240DRF (Compact), 230VAC, Screw terminal block, max. 4 extensions modules

TWD LMDA20DTK (Modular), 24VDC, MIL connectors, max. 4 extension modules. (Check, if you need to order mil connectors separately for this PLC)

Click to expand...

I don't need to check anymore cause i needed 230VAC power supply..so i choosed the first option..