Modbus RTU Selection

Hello all

I need help in choosing a Modbus RTU for educstional/testing purposes.

I use 1214C DC/DC/DC PLC which have modest 2AI at 0-10V.

Now, I have access to hundreds of PT1000 sensors and I want to make use of them. I figured RTU would do the trick. I aldready bought CM1241 module and the connector now I need you to help me choose the RTU which does not have to be huge. If it has inputs for say (5-10) PT1000 sensors that would be enough for me. 

Thanks!

uname-a

Hello all

I need help in choosing a Modbus RTU for educstional/testing purposes.

I use 1214C DC/DC/DC PLC which have modest 2AI at 0-10V.

Now, I have access to hundreds of PT1000 sensors and I want to make use of them. I figured RTU would do the trick. I aldready bought CM1241 module and the connector now I need you to help me choose the RTU which does not have to be huge. If it has inputs for say (5-10) PT1000 sensors that would be enough for me. 

Thanks!

Hello.

What is the link between the PT100 PT1000 sensors and Modbus RTU?
Do you have transducers as Modbus slaves for those?

Any specific reason that you are not wanting to use the
6ES7 231-5PF32-0XB0
signal module that can directly handle x8 PT100 PT1000 sensors?

qwazee

 

uname-a

Hello all

I need help in choosing a Modbus RTU for educstional/testing purposes.

I use 1214C DC/DC/DC PLC which have modest 2AI at 0-10V.

Now, I have access to hundreds of PT1000 sensors and I want to make use of them. I figured RTU would do the trick. I aldready bought CM1241 module and the connector now I need you to help me choose the RTU which does not have to be huge. If it has inputs for say (5-10) PT1000 sensors that would be enough for me. 

Thanks!

Hello.

What is the link between the PT100 sensors and Modbus RTU?
Do you have transducers as Modbus slaves for those?

Any specific reason that you are not wanting to use the
6ES7 231-5PF32-0XB0
signal module that can directly handle x8 PT100 sensors?

Maybe the title was a little bit misleading.

The reason I don't use the module is simple. Snapping the CM on the PLC is easy, but communication via modbus is something more challenging for me.  The company I work with uses PT1000 sensors wired to a Aucxis cards which is further wired on the PLC, but since they are custom made there is absolutely no info on them as to what kind and/or where to find them and have some starting refference in this field.

What can I you suggest as a link from the PLC to the sensors? 

Thanks.

uname-a

Maybe the title was a little bit misleading.

The reason I don't use the module is simple. Snapping the CM on the PLC is easy, but communication via modbus is something more challenging for me.  The company I work with uses PT1000 sensors wired to a Aucxis cards which is further wired on the PLC, but since they are custom made there is absolutely no info on them as to what kind and/or where to find them and have some starting refference in this field.

What can I you suggest as a link from the PLC to the sensors? 

Thanks.

Did you follow the link I have left you in my previous reply? Attached is some more information of a card that can make the PLC read the PT1000.

I opened the link and I have seen the module.

The thing is - what if I want to measure 5 separate temperatures at a distance of  over 100 meters? Thats 5 cables x100 meters.

I could however use 1 (2 wire) cable + power and mount a RTD Profibus slave close to the PT1000 sensors.

uname-a

I opened the link and I have seen the module.

The thing is - what if I want to measure 5 separate temperatures at a distance of  over 100 meters? Thats 5 cables x100 meters.

I could however use 1 (2 wire) cable + power and mount a RTD Profibus slave close to the PT1000 sensors.

Profibus is not Modbus RTU.
The 100m specification is important.
It is not about using PT1000's that is "just lying around".

You have a very specific idea in your mind.
You are on a fishing expedition.
You do not know yet what you need.

Best you tell the forum what you know/have and what you do not know/have.
+ Do you know which Profibus slave you will use?
+ Do you know which communication card will go into the PLC?
+ Is the 100m the concern or must it also be Profibus?
+ Which other part do you have "just lying around" that you wish to use?

The more cards you put on the table, the quicker helpful answers can come.Good luck finding your answers.

qwazee

 

uname-a

I opened the link and I have seen the module.

The thing is - what if I want to measure 5 separate temperatures at a distance of  over 100 meters? Thats 5 cables x100 meters.

I could however use 1 (2 wire) cable + power and mount a RTD Profibus slave close to the PT1000 sensors.

Profibus is not Modbus RTU.
The 100m specification is important.
It is not about using PT1000's that is "just lying around".

You have a very specific idea in your mind.
You are on a fishing expedition.
You do not know yet what you need.

Best you tell the forum what you know/have and what you do not know/have.
+ Do you know which Profibus slave you will use?
+ Do you know which communication card will go into the PLC?
+ Is the 100m the concern or must it also be Profibus?
+ Which other part do you have "just lying around" that you wish to use?

The more cards you put on the table, the quicker helpful answers can come.Good luck finding your answers.

- I don't have a specific idea, the 100m distance is not a concern now, but it is something to have in consideration in case I ever need it. Its easy plugging the sensors in the module next to you. Making them work over other protocol and third party hardware is not. 

- The PT1000 sensors are not "lying around" they are actually leftovers (used to measure outside temp on stainless steel pipes) now they are changed with in-pipe 4-20mA sensors due to accuracy. Around 150 sensors which are keeping dust in the warehouse. I can use those for start.

- For master CM I have 1241 as stated in post #1 (if it will work).

- For slave I have nothing as of now, I need suggestions on this one. But I am not thinking other PLC with RTD module.

I may have used terms which I didnt intend to due to not being familiar with how things actually work, thats why I am here, guess you can call it phishing expedition.