Hello,

only little addition to good advice from qwazee. As he also mentioned, RS485 doesn't mean automatically Modbus protocol. This is very important to know what protocol is used, although I expect Schneider Modbus capable generally.

Hello,

if I could say my opinion, it looks to me really like ASCII and not Modbus protocol. Is any documentation to that PLC and keypad what really messaging is used between keypad and CPU? I just think about quick test, attach PC with suitable USB-RS485 adapter connected to only keypad. On PC some useful SW like Hercules can be used with correct serial parameters set, then it can listen on serial port and check what you click on keypad. I'm really curious to that messages, how they are looking, better in hex format like f.ex. 01 FF 02 3A, simply I expect each key will generate unique byte sequence that PLC need handle. Then you can win with this problem, you can then easy prepare your PLC code to clicked key respectivelly do some procedure depended to that. If you can do this tests and attach here that messages how they looks like, be careful with correct data. Then we can say for sure if this is Modbus or Freeport protocol via ASCII as qwazee mentioned.

heh,

qwazee indeed good idea. I think from first look that left side is correct with comm settings, right is only some test or previous data??? I expect in this case that keypad need use same comm settings like CPU (correct me qwazee if I'm wrong). Really I don't know if keypad is connected to that 'left side"serial port so I expect still use my sugestion or if it's problem now, use that right SW tester as RTU Slave configured and see what will happen. I'll be do that by my self as I've mentioned, simply really isn't clear to me in case of Master/Slave system how it can be possible with keypad. Simply keypad can be only transmitter in case of pressed key and Slave (PLC/PC) can listen on port. If you can, make tests or maybe qwazee give other useful sugestions as usually.

Other idea. I think that better will be general serial SW like that Hercules (I use my own created) for listening on Port because we don't know where that keypad write data, to what register and with what length. With Hercules you can see first incomming byte sequence and then it can be checked what is inside, I think simply and quickly. If that right side (on picture) SW tester can simply 'translate'incomming message to correct visible data, then better.

Hello,

ok, no problem. Can you provide order number of that Keypad? Or link to manual? Without to know close infos about that keypad functionality we can't go further in my opinion. That test is really required.

Update: sry to not check SW, I have limited options now with Siemens SW... I still expect PLC as RTU Slave so you need configure MB_SLAVE block inside S7-1200 and with same comm properties as Schneider has on picture (speed, data bits, parity, ...). That can be way for tests in case that Keypad looks to me like Modbus Master here.

Hello,

very sry. With this info is help not possible. You can do what I recommended already to you, check all messages comming from jeypad to PLC or PC SW and then build your PLC code due that messages. Try prepare that Modbus RTU Slave block on S7-1200 then and make tests. If you don't provide more clear infos, we can't help better, sry.

Hello,

try that simple test with Hercules and PC connected to that Keypad, if you put some key some message need apear on Hercules box. That message can be copied here and can investigate next if you can. No other help now really, sry. I see this way as only one here to go further. 

Simply i expect these steps (if I need make this prj):

1. hack that keypad messages depended to each key pressed on keypad.

2. due that message format can say for sure if it's Modbus protocol or other maybe internal, who know.

3. due this important hack of keypad I can prepare PLC S7-1200 project, all depends to that point 1,2. If I know that messages structure I can simply then prepare PLC code to that keypad keys required action, simple.

Finito.

Update: maybe better explanation of point 3 to be in, this means 2 possibilities. You need due used protocol prepare serial communication on S7-1200. With Modbus RTU it can be maybe better because library is available and due hack of keypad can expect maybe some problems with correct answers with Slave PLC. In case of user defined protocol you need completelly program that serial by yourself with some blocks and in this case that hack of messages from keypad must be very precise. I see that hack most important. I don't know what way you'll select, we can help here to you as much as we can, without doing your job of course.

Hello,

hmmmm looks like something is there but better will be see it as HEX format. Sry, I don't use Hercules (use my own SW). Try find so where it can be set to HEX representation or better see that mesages. Just one thing - success  messages are there but pls try monitor. Messages are comming cyclically or only after key pressed? If HEX format isn't available try find other suitable serial SW and check.

Update: maybe also SW used by some users here with Modbus (ModScan or similar, also not used by me) can be better in this case, try find it, set it as MB RTU Slave (that original Schneider has RTU address 1) with that comm settings and we hope will see it better.

Update2: hmmm but from that screenshot it looks to me ok, I expect you pressed keys on keypad and some messages looking differently  that chars are not ok so try find HEX so it can look like FF 01 30 3A ...     This will be better because your windows char set is Unicode here and hard to understand then ASCII code.

Hello,

eeeeeeeh that Hercules isn't good, now I did test and with hex you can only send (bottom option). received messages it interpret only as chars what is unusable definitelly (for programmers and debug). Ok, try find other serial SW and in last case that Modbus SW.

Hello,

yes agree with you Marcian, swap of signals in this case (RS485) is expected. I'm wondering more about not possibility to hack correctly that Keypad and somehow also no experience with this problematic (Freeport/Modbus possible protocol). Without to know what protocol is used, no way to go further. If programmer have experience with serial communication and can differ quickly some protocol differencies visually, his work can be more quick with success. Next depended programming on S7-1200 side due existing protocol and message keypad type is required. Without to know this is simply not possible go further. programming simply will be different due existing protocol. User have some good recommendations from our side, question is his experience. On other side that ZAP13 prj tried open my friend and say it's impossible due some strange requirements. I can't say, I have limited possibilities now so can't open that ZAP13 project. On other side, is not useful now because we don't know base problematic - keypad protocol functionality.

Hello,

thnx for good info. No problem then, with your info about filling cyclically without key pressed is now more clear about that keypad. That HEX representation messages are required to see or check Schneider PLC code and find solution there but I see this hack as better. If you'll have next questions, go ahead. Perfect you've found other serial SW, hope it can show better incoming frames.

Hello,

very interesting update, can you pls tell us some background? I see very specific data storage areas so you have some infos about data structure? Simply as I said before, you need hack that messages, no one can help you, sry. Without documentation to that keypad you will have hard work till success. What is background till this your update?

Hello,

I very enjoy to your status about success! Wish good luck to next steps to finish your prj. No problem continue here with other questions.