ORSO2001 Posted December 18, 2018 Report Share Posted December 18, 2018 Hi All, I'm using the UniStream as a slave connected by Modbus TCP. Is there a way to know/check the forwarded data, by the Master, byte to byte? thanks Quote Link to comment Share on other sites More sharing options...
dierkens Posted December 18, 2018 Report Share Posted December 18, 2018 47 minutes ago, ORSO2001 said: Hi All, I am using the Unistream PLC as a slave connected by Modbus TCP...exist a way to know/check the forwarded data, by the Master, byte to byte? thanks Not sure why you want to ( error checking, byte manipulation, etc)? Read this and see if it answers any of your questions. https://www.rtaautomation.com/technologies/modbus-tcpip/ Quote Link to comment Share on other sites More sharing options...
ORSO2001 Posted December 18, 2018 Author Report Share Posted December 18, 2018 hi dierkens thanks for answer....maybe my explanation was not clear...my PLC works as a slave...i create some registers (read, write) for a master (that is not mine)...who has created the master program is saying me that the comunications is not working...but if i use a program test to check my registers all works fine...i need to know what they are passing me. Quote Link to comment Share on other sites More sharing options...
dierkens Posted December 18, 2018 Report Share Posted December 18, 2018 51 minutes ago, ORSO2001 said: hi dierkens thanks for answer....maybe my explanation was not clear...my PLC works as a slave...i create some registers (read, write) for a master (that is not mine)...who has created the master program is saying me that the communications is not working...but if i use a program test to check my registers all works fine...i need to know what they are passing me. You should use something like a MODSCAN to test the reading/writing of registers/coils on both ends. Although you indicate that your PLC works as a slave, you must mean that they are sending the MODBUS register information to your PLC. You can use WIRESHARK to get down to the packet level of information; but that level of detail typically isn't needed. Can you ping the MASTER device? Can the SLAVE ping you? Have you checked the OFFSET to make sure that both devices are using the same array start [Zero (0) based versus One (1) based register assignments]. Start with something easy like coils or a lower register. Just use some basic MODBUS troubleshooting techniques. Quote Link to comment Share on other sites More sharing options...
ORSO2001 Posted December 18, 2018 Author Report Share Posted December 18, 2018 hi dierkens, thanks again for your answer...now I have 5 minute of "relax" to try to explain better what I have. to be clear ...when the phisical installation was started my PLC was ready, program done, test field simulation etc, to be connected with the master...obviously I wrote a data exchange document with all explanation...also a step by step example... was who had to program the master side that was not ready...and develloped the program at customer site! at the time I have connect the PLC with the PC where I created an easy program in C# to test...to show at the end customer that all work fine...and it was. after a few the second supplier told me that they were having problem because they never used Modbus protocol (but was the agreement from the beginning!?)...I explained again what they had to do...after a few they told me "now is ok"....great I thoug...but now they come back telling me that sometimes the command is not catch...in my PLC I have a "debug page" where I can see the amount of the "success" and "failed" about the TCP side...the fail are always "0" and the "success" increased every time. in their PLC they don't manage the exception or the data send error or don't check "my" registers about alarms or wrongs commands....I know because the customer user don't found these when the system seems not working...and they (second supplier) are not telling me how they are creating the data string that are sending... yes I can use something like a "sniffer" but I was thinking if the buffer of the data entry was available!? Quote Link to comment Share on other sites More sharing options...
ORSO2001 Posted December 19, 2018 Author Report Share Posted December 19, 2018 dears...sorry if I am wasting your time...but I have an update...seems that they (second supplier) have found what they were doing wrong...I don't know what exactly they have do but from yesteday the system is working without problems...and I am happy! thanks Quote Link to comment Share on other sites More sharing options...
Gabriel Franco Posted December 20, 2018 Report Share Posted December 20, 2018 It would be great to have a serial comm monitor in Unistream like in Vision. This tool is the first I use to check comms problems and let me check at HEX level. Quote Link to comment Share on other sites More sharing options...
dierkens Posted December 20, 2018 Report Share Posted December 20, 2018 1 hour ago, Gabriel Franco said: It would be great to have a serial comm monitor in Unistream like in Vision. This tool is the first I use to check comms problems and let me check at HEX level. Agree... couldn't agree more... Quote Link to comment Share on other sites More sharing options...
MVP 2021 Ausman Posted December 20, 2018 MVP 2021 Report Share Posted December 20, 2018 Ok Gabriel, time for me to learn something. Serial comm monitor in Vision? Has this been staring me in the face for years without noticing it? cheers, Aus Quote Link to comment Share on other sites More sharing options...
ORSO2001 Posted December 20, 2018 Author Report Share Posted December 20, 2018 Quote 2 hours ago, Gabriel Franco said: It would be great to have a serial comm monitor in Unistream like in Vision. This tool is the first I use to check comms problems and let me check at HEX level. Agree... couldn't agree more... obviously...me too Quote Link to comment Share on other sites More sharing options...
MVP 2021 Flex727 Posted December 20, 2018 MVP 2021 Report Share Posted December 20, 2018 1 hour ago, Ausman said: Ok Gabriel, time for me to learn something. Serial comm monitor in Vision? Has this been staring me in the face for years without noticing it? You're not alone. Quote Link to comment Share on other sites More sharing options...
HigHTech Posted January 3, 2019 Report Share Posted January 3, 2019 On 12/20/2018 at 4:47 PM, Flex727 said: You're not alone. You run that on info mode. Quote Link to comment Share on other sites More sharing options...
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