markyspicer

FX3U-485ADP-MB

16 posts in this topic

Hi!

I have some concern dealing with the FX3U-485ADP-MB device which will be plan to install and a total of 17 modbus devices(Chinese brand converter 4-20mA to RS485) where going to communicate. I'm new to this feature of FX3U family and I'm using GxWorks2. Is there anyone that can guide me through this device/development? Is there a program block for this like the one I have been use for analog modules(FX3U-4AD)?

Looking forward to your help!

 

Thanks a lot!

Marky

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What would you like to know?

Have you downloaded the manual?

 

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Hi Gambit!

I'm already working on regarding the FX3U-485ADP-MB. Also I have downloaded the "FX3MBModbusRTUMaster_PRG" FB from the mitsubishi website but my problem is that how can you communicate? I have no idea when it comes to mitsubishi rs485 on how will you execute(using GXworks2). I have the device slave addresses but I'm still checking which modbus address would I extract in order to read in the mistubishi pLC. I need to read the process variable of 17 analog devices, no control. for monitoring purposes only but I'm lost when it comes to interfacing the RS485 Module devices going to the FX3U-485ADP-MB. Hope you can help me on how to execute/established even 1 or 2 devices so I can work it around.

Everyone's help would be really appreciated.

Edited by markyspicer

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The first thing you need to find out are the communication settings of the modbus devices.

  • RTU or ASCII
  • The Communication settings 7 or 8 bits, parity , nr of Stop bits
  • Which Holding or input register\coils contains the information you need
  • set up each unit with a slave number (1-31) 

Have you got this information  ?

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The device is an Modbus RTU. I'm using this KH-7018 Khoat 8 Channel Isolated Input Module. The device slave addresses are as follows "Capture". While the Holding register is that what I'm confuse about which I have the manual for the devices. Please see "KH 7014-18 MANUAL". total of 14 level transmitters and 3 flow transmitters which are 4-20mA comms. Further I'm stuck in this information.(capture1)

Capture.PNG

KH 7014-18 MANUAL.pdf

capture1.PNG

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Each adress is mentioned in the manual

For channel one 40000
For Channel two 40001 

etc.

In your program use only need to use 0-7. 
sometimes there is a -1 0ne issue so i would try an d read holding register 1 and see if that is channel 1 or channel 2

 

 

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That's the part where I'm confuse about. I haven't try to program mitsubishi with rs485 before. hope you can guide me even 1 device sample if you have some spare time.

Edited by markyspicer

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okay what are your Questions ? Have you read the help file for the FB?

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yes, but I'm confuse on how to tag it(to much data which I think its not necessary for my program which is reading data - "READ DATA" only) . Is there any solution which is minimal programming done in order to extract the process variable of the devices? Also if I'm going to use this Modbus Comm Block, is it sufficient in order to retrieve all the data needed or should I need to duplicate the block as per devices?

Untitled.png

Edited by markyspicer

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In post #5 all the POU's are 'red'. Is it because they are not compiled, or are they not registered in the task manager (not executed)?

 

Just now, markyspicer said:

is it sufficient in order to retrieve all the data needed or should I need to duplicate the block as per devices?

You set up one block, and if you need more than one Modbus request you set up a sequence of requests in the surrounding program structure.

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This is the connection of devices. Using only the FB(Modbus Comm.) block can perform the data receiving or it will be only one block for 1 FX-485ADP-MB? or it is more suitable to use the ADPRW? Honestly I'm very lost at this moment when it comes to mitsubishi FB.

@kaare_t I'm still not compiling the program.

Untitled.png

Edited by markyspicer

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Why are you not compiling the program? 

If you are worried about program sizer Maybe you should just write the  ADPRW instructions. What would you like to do?

 

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Hi,

As far as my understanding, using the "FX3MBModbusRTUMasterCH1" usually/default reading is a single device? so you have to add multiple ADPRW blocks for the other devices? is it right?

Thanks for your reply

Edited by markyspicer

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Hi!

Can somebody tell me if the program I created will work based on my understanding? I have compile the program no errors detected.

Appreciate your help so much!

Thanks!

Capture.PNG

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On 16.02.2017 at 2:34 PM, markyspicer said:

Hi!

Can somebody tell me if the program I created will work based on my understanding? I have compile the program no errors detected.

Appreciate your help so much!

Thanks!

Capture.PNG

Will not work. Modbus address 40000 for program will be 0. Also you didn't check modbus communicating flags, also you can read all 8 registers by one request. Make something like this. Using a lot of continuously adprw a bad idea. Better make slave address 1,2,3,4. Why did you skip 4?

vcv.jpg

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Thanks @Clear.Mind!

I will update this post on what will be the outcome. :notworthy:

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