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I need to let the Pt100 dat3014 acquisition modules communicate with a mt8050 for the temperature display! I find it difficult to display the temperature! In the context of the device I entered:
Modbus rtu (zero based addressing)
COM1 (9600 and 8 1) the device has been programmed with the same settings
1 plc station (address programmed in the 1 module)For the display use a numeric:
Name plc modbus rtu (zero based addressing)
4x address. 40015 which is input 0 of probe 1 shown in the dat3014 manualCoils with 00001 address up to 00008, using the bit lamps go great, and detect the failure or interruption of the Pt100 cables. The display of temperatures do not go, the terminal tells me Plc no response! Here is the link to manual of the form.
How can I fix the problem?
The standard Modbus protocol has offset 1, you have chosen zero base addressing mode and therefore you have eliminated the offset. However, many devices work without offset (it may be that the DAT3014 is also like this) but the offset at the limit will offset the addressing by 1 (Just add or subtract 1 to the address to fix it).
The fact that the Coils work however means that the addressing is correct, now as regards the WORD registers reading the manual it seems to me that the 4x command operates on the 3xxxx bank registers which are the mirror of the 4xxxx registers. So I would try to use the address 30015 instead of 40015.
For the analog acquisition of Pt100 / 1000 especially if you have many points I suggest you take a look at our modular system SlimLine with its analog I / O expansion module.
Hi! Thanks for the reply. I tried using the 3x 40015 and 4x 30015 command but the problem persists! I noticed that the number is not displayed at all! And after a few seconds the terminal says PLC no response.
I did a myriad of tests but nothing, I also tried in ascii reprogramming the DAT3014! And even using a rs485 / modbus TCP converter. I am using the DAT3014 because I have a couple at home, and I wanted to use it for a prototype project, I have already considered using your products!
If the terminal displays PLC no response, it means that it does not receive a response to the Modbus command it sends to the device, usually due to an address error. The documentation of the device is not very clear and above all there is no example of a Modbus frame.
I suggest you try a simbus program on PC (Example Modbus Master Simulator) to try to understand what the Modbus commands the product accepts.
If you know the Modbus protocol, you can also try our program Toolly which allows you to send binary strings over serial and also has a practical CRC / LRC calculator for Modbus protocol in the utilities (See the last post of this topic).
Try to make a project with a data visualization object in the default page and point it to 3x 40016 instead of 40015. You have chosen modbus zero based addressing and therefore there may be a difference of 1 on the addressing and I have seen that register 40014 is reserved .
Reading a single 3x 40016 register whether there is a positive or negative offset is always fine ... at the limit you read a value other than what you think.
Tried and tested no improvement! I also used the modbus tcp ip protocol using an interface converter but no result I give up ...
Well after a myriad of tests I solved it by setting Modbus TCP / IP protocol going to read the 4 × 16 address and not 4 × 40016 And the 3 × 16 address also works.
Problem solved thanks a thousand of everything!
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