FX and Profibus Async message

[panic mode 246]

Hi everyone, I helped customer setup small profibus network and so far everything is good but I am looking into making use of asynchronous profibus messages from FX3U (with 64DP card). I am reading manual right now but due to time restrictions I have to ask if anyone may have working code sample they may be willing to share. Regards,

[Veganic 8]

I think it can depend very much on what you are reading/writing from. I'm working on a function block for this in GX dev for Q series at the moment though I don't know how generic it will be. For reading I have to first write a message block then repeatedly read until I get the correct reply. Writing is simpler by comparison. Mitsubishi website have IEC blocks but I can't get into them as I don't have IEC 7.xxx

[kaare_t 155]

Hi. I haven't worked with the FX3U and Profibus, but I have GX IEC (7.01 / 7.03), and I could export the Mitsubishi function blocks as IL if you would like. I'm not sure if you can use it as IL in GX Dev. (or do you have any other idea?).

[panic mode 246]

Thank you kaare_t, let's see what it's like in IL then.

[kaare_t 155]

I assumed that Mitsubishi actually had a function block / program example for acyclic transmission for the FX3U. Veganic: Where in the Mitsubishi web-site did you find the IEC function blocks for FX3U and acyclic transmissions you mentioned? Sorry panic mode, it doesn't seem like Mitsubishi has any working example for acyclic transmission with the FX3U-64DP card. I can check if anyone at work has ever made a program for this kind of communication, and if so, I will send you the code. As mentioned, I haven't worked much with Profibus, so I'm not sure if I understand exactly what you need. Could you please explain exactly what you need to do, so that I can ask "the correct" questions at work tomorrow (and get the correct code if there is any)?

[Veganic 8]

Veganic: Where in the Mitsubishi web-site did you find the IEC function blocks for FX3U and acyclic transmissions you mentioned? It's for the Q series. ProfibusDpv1Q_V200 GX IEC Developer 7.00 function blocks for acyclic read/write operations between a QJ71PB92V PROFIBUS-DP Class 1 master and PROFIBUS-DPV1 slaves. I'd assumed that there would be more similarities than differences but having looked at the FX3U-64DP manual I was probably mistaken.

[panic mode 246]

PLC is connected to a slave that has several "modules" inserted into sort of a backplane. Slave (and it's modules) have fixed configuration for cyclic communication (fixed number of I/O bytes). This works and PLC is getting readings, status etc from all of them. The fact is that this I/O map is fixed so to set parameters for example etc. one must use acyclic comunication. I don't have hardware here so I'm reading manual (which is only 130 pages).

[kaare_t 155]

I'll check with some people tomorrow, will let you know!

[panic mode 246]

after comparing content (specially timing diagrams) of the sections: 6.24 (Cyclic Data Output) and 6.26 (Acyclic Data Output) it look like everything is pretty much the same. btw. i've came across error in code example in manual on page 108, fourth rung, where they used BMOV K1 U0\G225. this is of course rejected by program and one should use MOV instruction instead of BMOV.

[kaare_t 155]

Sorry man. I've checked at work, and also a couple of other companies we work together with, but it seems like no one has used acyclic communication with the FX3U profibus master. Sorry for the "false hope" in first post and good luck!

[panic mode 246]

no problem, it's all done and working nice. thanks for trying, that's what counts.

[abd_kurdi 0]

I have a profibus communication using FX3U-64DP-M to access a profibus slave the only thing I want is to monitor the slave outputs can I use it as one way communication ?