Hello Gerard,

pls look, sry but we probably are again outside of our area. I think that we already talked about RK512 and 3964 protocol in first posts and we decided that this isn't our destination (destination can be f.ex. with S5 system). Our protocol selection on CP340 is ASCII, or your situation had changed? In this case your posted document is simply irelevant for you, also FB blocks that depended to that posted protocol. Simply if you put CP340 with TTY, you must know why you want use that TTY and not RS-232/422/485 interface. All depends to your communication partner specification. Sry but from begining I still read only that you're experimenting, but other way can be experimenting due your gived task, project. Till this time I don't know what is your communication partner, what are it's communication requirements. I'm very sry, but giving you little example, pls try understand it, you ask me how to build a car, I giving you simply you need wheels, lights, ... But in the middle of our talk you ask that you need build Porsche. In this case all our work, talk was waste of time, if you had posted on begining all relevant infos our talk can be maybe in other areas... I know that you're probably investigating, learning new things, but you have in close to you people that must know why you want use that HW, why not other type. Pls think about this everytime  Back to work, simply if you don't have that library, you don't have chance use it, forget about implementation of that, you must prepare your code manually, also that CRC/LRC. You have only FB2 and FB3 for that, nothing else. As we discussed before, there is also that implementation of Modbus on CP340 without buy CP341 and other needed accessories. Really I must say again, never used that. What are your thoughts now?

Ok, probably will be better sum up again my opinion to your work:

1. you can implement Modbus ASCII communication by your own implementation, via FB2,FB3 with CP340 - RS232, RS485/422 or TTY module. Can be hard to program but can work. Also can be maybe not realisable, all depend to you what you'll post here in future, mean changes

2. you can buy CP341 (RS232 or RS422/485) with Modbus support (prepared Modbus libraries - you must select protocol which you can use - what you select you must pay for it) + domgle with driver. As I said, you have here all prepared, also that CRC calculation, simply only construct instructions with proper logic with input parameters, everything next is automated. For this solution you must simply pay.

3. you can implement that MODBUS ASCII user library created by our friend with CP340. It's free but I never tested it, as I said in my previous post.

If I forget something or post wrong, pls other guys post corrections.

Duris,

Sorry if i make confusion about the direction we are going,  Also for the difference in level between you and i concerning the subjects were discussing.

At our site we have lot of siemens cpu's with stuff (io do ai ao etc) also a lot of other machines which uses cpu's.  Interest in this stuff i bought a cpu with some modules myself to experiment/hobby.  But now i see possibilities to optimize the process at our site. One possibility is to let our cpu communicatge with a slave. The main point/problem is (as you also say) i don't know exactly what the slave is. First i was told it is rs485/3964r, so i bought a module for this, but then i was told it was modbus, so i thought (after some posts with you) "with some crc tricks my rs485 module will be compatible". But now they've told us that slave is probably a 20ma current loop. So i also kind of lost track in this. But i already bought a module for this to investigate this. but now i'am waiting for the supplier of the slave to give some more info about the interface

Through the time the slave also evolved and many types are used (told me). the newest version of the slave uses a modbus tcp ip interface, but that is to none importance to us.

if you want more information, perhaps i can send you private message with more details

gr gerard

Hello Gerard,

thnx for post. No problem my friend, you can post news everytime to show us how it's going. Don't hesitate ask everytime if you'll decide to. Have a nice day.

Hey Duris,

I'am experimenting some with my cp340 rs422/485 card and my cp340 20ma tty card, and i both put them on the same rack next to my cpu 315-2 dp. but i noticed that it is not possible to program them at the same time.

example:  if i programe one card i need from the library fb2 and fb3 and put them in fc1 then i get automaticly fb2 and fb3 in my block overview  (those 2 fb's then get a 'lock' sign, see attachment).

but then when i try to program my other card in fc2,, again with fb2 and fb3 from the library then i think the problem starts because i need those 2 fb's with the lock again and i get a lot of messages but don't see those 2 fb's twice.  how do i solve this. 

also in attachement i see sfb 52 and 53. they are there and they came with my program. but how can i figure out in the programme wherefore they are(which fb uses them). or is it always with sfb that i have to take them for what they are and take them for granted.  

gr gerard

gerard32

Hey Duris,

I'am experimenting some with my cp340 rs422/485 card and my cp340 20ma tty card, and i both put them on the same rack next to my cpu 315-2 dp. but i noticed that it is not possible to program them at the same time.

example:  if i programe one card i need from the library fb2 and fb3 and put them in fc1 then i get automaticly fb2 and fb3 in my block overview  (those 2 fb's then get a 'lock' sign, see attachment).

but then when i try to program my other card in fc2,, again with fb2 and fb3 from the library then i think the problem starts because i need those 2 fb's with the lock again and i get a lot of messages but don't see those 2 fb's twice.  how do i solve this. 

also in attachement i see sfb 52 and 53. they are there and they came with my program. but how can i figure out in the programme wherefore they are(which fb uses them). or is it always with sfb that i have to take them for what they are and take them for granted.  

gr gerard

 Hello gerard,

 Why you want to resume FB from the library twice? they 've already ... When you call them that are seen in FC, FB you must associate them with a different DB , I do not know what language you use , but in STL e.g.:

FC1:

CALL FB2,DB20

CALL FB3,DB21

FC2:

CALL FB2,DB30

CALL FB3,DB31

Have you already tried that?

Hello Gerard,

yes as Ste posted, if you want use 2 independed CP cards you need have 2 different store memory to see statuses from both CP cards, simply you cant use one DB block (in your case DB2,DB3 for both cards), because that status from one CP f.ex. SEND - DONE isn't same as f.ex. on second CP card, so therefore you need to differents memory. Communication blocks are used same - FB2, FB3, but with call of needed FB2, FB3 you need add needed DB block which depends to needed CP card. In SCL I was prepared that with create of some SCL source where I defined needed DB block depended to FB2, FB3:

DATA_BLOCK DB2 FB2

BEGIN

END_DATA_BLOCK

DATA_BLOCK DB3 FB3

BEGIN

END_DATA_BLOCK

DATA_BLOCK DB4 FB2

BEGIN

END_DATA_BLOCK

DATA_BLOCK DB5 FB3

BEGIN

END_DATA_BLOCK

Here you see 2 different DB blocks asociated with FB2 - DB2 and DB4, so f.ex. for first CP card you'll have statuses in DB2 and for second CP in DB4. So if you compile this SCL source it make needed DB blocks as you need for independed functionality.

Update: for understanding correctly this situation, simply you can also use one FB2, FB3 with their only DB2,DB3 instance data blocks with both CP cards, but only one CP card on one time, not both CP communication on same time, in this case you'll need implement some kind of selection controller to drive your communication correctly. With defined another instance DB blocks you can drive your communication with both cards on same time independently.

yes Duris and Ste,

i programmed it in lad/fbd,  i think i know what you mean, i'am going to try something.

gr gerard

Hey Duris,

At the moment i am programming my cp340 tty to read out my slave, but perhaps a stupid question.

my intention is to read out my slave as much possible, when a read out is finished the next read out/request comes straight behind it.  so the cp340 working for the whole time request after request. But all that work for the cp340 card,  how is that with wearing out of the card. Now i'am programming, i just get the sense that with all that work i have for my cp340 card. it won't last that long, is there any information about that. 

i also bought a cp343 card for prospective reasons in our application,  i assigned an ip adress to it and it works, in a network i can find the cp343 and monitor it with step7, but how is it possible that when i log on to our router, the router shows all the devices with ip adress that are on to the router, but the cp343 i cannot find also not a trace of the ip adress from the cp343 is found on the router,

gr gerard

Hello Gerard,

I don't think so for that wearing of CP340, isn't important. Had some old projects where CP340 acts as Master on user communications many years without problems, mean uninterrupted communication with request after request 24h to Slaves  I don't know about your router configuration, probably your IT division can help you with this. In other way maybe some Port opened/forwarding can be made, also correct Gate configured to see/work correctly on your Net.