smartdesignmike Posted April 6, 2017 Report Share Posted April 6, 2017 Where can I find out what the advanced Modbus commands do? Help does not have anything as well as the online help. Quote Link to comment Share on other sites More sharing options...
hotwires Posted April 7, 2017 Report Share Posted April 7, 2017 Mike, I've been told by UniTeam (Isreal) that a Unilogic release is coming soon with a (more) complete help section. You can always call tech support, that's what I did on my first Unistream project. It was a SCADA system with 4 RTU's; MODBUS was pivotal. Dan Logee at UniT east coast was able to answer/resolve all my questions/issues. Quote Link to comment Share on other sites More sharing options...
Meeg Posted December 14, 2017 Report Share Posted December 14, 2017 Hello. I have the same question. Is there any detailed description somewhere yet? My problem is Reading 2 values from a sensor. Using a Modbus simulator it Works fine from my PC, but not from the PLC. The communication from my PC is shown in enclosed file. When I use the "Modbus Read Builder" it seems that the "request buffer" is the same as TX in the enclosed document. But I am not sure if (or how) to use the "Read parser" to get the answer? Thanks for an excelent software! Regards Anders Meeg Modbus to DS80.docx Quote Link to comment Share on other sites More sharing options...
ORSO2001 Posted December 14, 2017 Report Share Posted December 14, 2017 Dear Meeg, have you tried to take a look at the modbus advance examples (RS232, 485 and TCP); also, have you tried with the video tutorials? I found these very helpful for me and now all my projects that include modbus work very well...both as slave, master or together. how ever if you will post the part of the code where you are trying to use the parser (write and read), maybe, we will find the issue. Quote Link to comment Share on other sites More sharing options...
Meeg Posted December 18, 2017 Report Share Posted December 18, 2017 Thanks for helping ORS! I only had the the old example projects downloaded (from V1.15). With the help from the Advanced commands in V1.19 I was able to see that the commands was OK. It turned out to be a hardware problem. The sensor (ECD DS80 conductivity sensor) was not 100% rs485 compatible so I had to turn of the resistors on the CPU and use a 1k resistor instead. By the way, do you know why it is 2 resistors on the CPU? And what size and how are the resistors connected? The CPU manual does not give any details and normally only one 150ohm is used for cable termination. Is the two resistors for "pull up" and "pull Down" so that the line termination must be added externally? Regards Anders Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.