All right, I will ask one of the team to add the modbus delay parameter to the T3-LB series
Hi @maurice,
today I did an experiment with one of my WAGO controllers and set up a poll of one Modbus register on TCP on it and similarly set up a poll on T3-LB, look what came of it: Temco T3-LB Modbus Polling Problem - YouTube
You see that the problem of T3-LB is not only in the pause between requests, but in a chaotic data stream. Is it fixable programmatically? If so, how long will it take?
Would you mind to use wireshark and send on the capture of this same test. We can work better from that than the movie.
Could I request a wireshark capture once again Aleksei, it will be much more clear for our engineers. Plus youtube is blocked in China.
Maurice
Hi @maurice , I did not know that YouTube is blocked in China. Tomorrow I will prepare the data you need.
Hi @maurice,
I looked at Wireshark, it does not suit us. The problem is that it does not work with COM ports (RS -232/485), only with Ethernet. In our case, the Temco controller is a Modbus master, which polls the slaves via RS-485. I suggest you use the DUNOVO SerialMon program, the trial version is available for download at https://www.dunovo.com/
To this message I attach a pdf file with a description of the problem and three log files for your analysis in the DUNOVO SerialMon program.
Modbus_Polling_Experiments.pdf (1.1 MB)
T3-LB_20191122.mon (10.8 KB)
Modbus_Poll_20191122.mon (2.1 KB)
WAGO_750-881_20191122.mon (3.1 KB)
I hope you can quickly respond to my message.
Thanks.
I didnt realize you are using Modbus over com port, we have some tools for that and will study what is going on here.
I checked the pdf file and use same capture tool to test, but did not find same issue. It is a basic freature as modbus master. it always woks well. Maybe you can give use more clues.
Hi @chelsea,
Hallelujah!
The problem of instability on the Modbus poll was in setting the RS-485/USB adapter. My adapter uses the Prolific chip in the settings which by default was set to “Low Latency Mode: 50,000 bps and less.” When I disabled this option the data transfer has started to work as it should.
Thank you very much for your check, which prompted me to this decision.
Good morning
I plan to test soon my first configuration with Nano controller and metzconnect triac output module on modbus
Basically to command the output, I would use MB_COIL command
Where can I find documentation about this.
Does it work on a Nano controller ?
Thanks for your feedback
Been meaning to write this up better, will get to it today. For now try with a few registers if you could, the MODBUS_REG commands are documented here:
Thanks Maurice.
I already found this before in the software manual .
So I can imagine that MB_COILS would work with same syntax.
Not sure that MR-TO4 triac output module are managing more modbus function than write coils.
Here’s some examples of the various modbus commands in control basic. Some are new and not fully tested in all environments, if you have any trouble let us know.
Where:
The Panel ID of the T3 controller is 3
And the Modbus ID of the subnet device is 5
10 REM **** Modbus Function Code 01: Read Coils
20 VAR1 = 3.5.MB_COIL1
30 REM **** Modbus Function Code 02: Read Discrete Inputs
40 VAR2 = 3.5.MB_DISINPUT1
50 REM **** Modbus Function Code 03: Read Holding Registers
60 VAR3 = 3.5.MB_REG1
70 REM **** Modbus Function Code 04: Read Input Registers
80 VAR4 = 3.5.MB_INPUTREG1
90 REM **** Modbus Function Code 05: Write Single Coil
100 3.5.MB_COIL1 = 1
110 REM **** Modbus Function Code 06: Write Single Register
120 3.5.MB_REG1 = 1