Sign in to follow this  
Followers 0
BenJones

ModBUS and CRC code

39 posts in this topic

Ben, For CH2 is need to use the FB for IEC Developer from Beijer company, which based on No protocol communication. The library is named as ModbusFX3UMaster_V100.zip: http://beijer.net/web/web_aut_en.nsf/AllDocuments/EDB9A5DF7DDF10A4C12571EE004ABB9D. The channel setup is performed by the function block.

Share this post


Link to post
Share on other sites
Hello, yes I have those function blocks. There is a function block for fo channel 1 and also one for channel 2. Is it possible (using the ModBUS protocol) to get both channels reading data at the same time using these function blocks ? Many thanks.

Share this post


Link to post
Share on other sites
Ben, I've not checked these FBs but think that you can use two function blocks for Ch1 and Ch2 simultaneously. But why you need in it?

Share this post


Link to post
Share on other sites
You cant use these function blocks siimultaneously. Channel 1 and Channel 2 cannot read MODBUS data simultaneously. I've been trying to sequentially switch the channels on and off to read the data. Ie. channel 1 on for ten seconds and read the data, then off. Then channel 2 on for ten seconds and read the data and then off, then back to channel 1 etc. Cant get it to work.

Share this post


Link to post
Share on other sites
You need to use two different function blocks to be able to use both channel 1 and channel 2 at the same time. You have downloaded the "FX Modbus Solution Pack" correct? Then you use the following: Channel1 (BD or ADP): ModbusFX3UMaster_V100.zip Channel2 (ADP): ModbusFX3UMasterADP_MB_V100.zip This will work.

Share this post


Link to post
Share on other sites
Ok, will try again. I think that's the one I have. In any case, I just downloaded it but I'm not sure how to install it. Doesnt seem to have a .sul file or restore file Is this the correct link : http://www.beijer.se/web/web_aut_se.nsf/docsbycodename/filearchive?OpenDocument&mylink=/web/BExFilePileAut.nsf/fm.be.searchframe?Openform&Lang=SE&DocID=B32726F09DFB2B33C12573C4005061D8 How do you install it Kaare ? Thanks again.

Share this post


Link to post
Share on other sites
This is my set up for the PLC. The mitsubishi guy said that this would work. I've enough today so it's time for a beer ! Thanks for all your help today. Ben Fx3u setup.bmp

Share this post


Link to post
Share on other sites
Ben, before begin to work is need to read documentation!!! Your configuration will not work, because is possible to install TWO communication modules only (including of BD).

Share this post


Link to post
Share on other sites
FX selection tools http://rapidshare.com/files/415301310/FX_Selection_Tool.ZIP

Share this post


Link to post
Share on other sites
Yes, the PLC does support 2 ADP cards. You can also get them to both read data together if non-protocol mode is selected. Howevever if the cards are to read MODBUS then both cards will not work simultaneosly by the looks of it. Tried FB's and also programming from scratch. I downloaded the F series selection tool as shown above last week. Tried to open it on 3 different pc's att work running XP and Visa platforms and the sofware doesn't open on any. Dont know what the problem is there. Come on Mitsubishi, sort it out !

Share this post


Link to post
Share on other sites
I thought you were running GX IEC Developer, hence my reccomendation using function blocks. Mitsubishi/Beijer have written the Modbus protocol in pure code so that both channels can be used at the same time (one of the cards is configured using the "built-in" Modbus protocol, and the other card uses the programmed Modbus protocol). Since you're using GX Developer I think you'll have to use only one channel (or write the Modbus protocol for the second channel.....).

Share this post


Link to post
Share on other sites
Hi Kaare, Yes I'm using GX IEC developer. the configuration I have is the FX3U_RS422_BD (NOT CLASSIFIED AS A CHANNEL) - used for transferring program from IEC developer to PLC. Left of PLC base unit - FX3U_RS485_ADP_MB (CHANNEL 1) - reading modbus slaves 1-6 Furthest left of PLC base unit - FX3U_RS232_ADP_MB (CHANNEL 2) - reading modbus - slave 7 This is the correct right ? I saw your post about the modbus function blocks which I have ! (Attached photos.) These are : ModbusFX3UMaster_V100 (used for channel 1 ?) ModbusFX3UMaster_ADP_MB_V100 (used for channel 2 ?) Which specific function block / program do I use for each channel ? Is it the ModbusFX3UMaster_RS2_CH1 program for CH1 and the ModbusFX3UMaster_ADP_MB_CH2 function block for CH2 ? I thought the RS2 program was for 'no-protocol' mode and this wouldn't work with Modbus ? Thanks again, Ben

Share this post


Link to post
Share on other sites
Hi! You cannot have a total of 3 communication cards!! You can either have 1 BD card and 1 ADP card, OR you can have 2 ADP cards. But a total of 3 cards will not work (not supported). Even if you use the BD card only for transferring programs this card automatically allocates Channel1, so the only channel you have left is channel2 (1 ADP card). Sure, RS2 will work for Modbus also. Mitsubishi/Beijer has written the Modbus protocol in ladder code so that you are able to use 2 channels at the same time (but 3 channels as you have is impossible).

Share this post


Link to post
Share on other sites
Thanks guys. Case closed. Have a great week, Ben

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0