Modbus watch list update

[punktea]

I have an RTU with modbus serial interface and I would like to use Mango to control it. I am a novice with Scada but I have successfully installed and used Mango to flip some binary outputs on the RTU without much problem. I have a couple of issues that I need help with:

1. I created 2 data sources, 1 for my RTU and 1 Virtual, and I added some points for both and used a watch list to monitor them. When I set a binary output of the modbus serial device to 1, the value on the watch list changed to 1 and I verified that the output on the RTU is now high. After a short moment, the watch list is automatically refreshed and the value on the watchlist is set back to 0. The output on the RTU remains unchanged. I do not see the same problem with I repeat the same procedure for a point of the virutal data source.
2. I installed mango on a PC running linux with 2 serial ports, /dev/ttyS0 and /dev/ttyS1 and the modbus serial device is connected to /dev/ttyS0. When I first created the data source, the port option allowed me to select either /dev/ttyS0 or /dev/ttyS1 and I selected /dev/ttyS0 and the data source is properly created. When I went back to edit it however, the port is now shown as connected to /dev/ttyS1 and the option /dev/ttyS0 is also gone.

The 2 problems above occurred on both versions 1.7 and 1.8. I have also changed from Derby to mysql with no improvements.

I also have a minor problem with 1.8. With first attempt to login, it will complain with
"NOTE: you may have problems with Mango because your browser is not officially supported. Please upgrade your browser". I am using the latest release of Firefox, 3.5.3. I do not have that problem with 1.7

[mlohbihler]

Hi punktea,

1. Check the history of the modbus point (assuming it is being logged). If Mango is working properly you should see that a 0 was saved sometime after the 1. There should be no source/annotation, indicating that the value indeed came from the data source (in which case you should check what the hardware is doing). Does this happen every time, or intermittently?

2. Sounds weird. I presume that when ttyS1 is shown as the port it is only because ttyS0 isn't in the list to show. It could have something to do with the RXTX library. Try this... When you only see ttyS0, disable the data source and refresh the page. If ttyS0 shows up again, it's probably because for some reason the port isn't being seen when it is in use.

I'm using 3.5.7 and i don't have that problem. Above that note it should say what browser it recognized. What does it say?

[punktea]

Thank you for your timely response.

1. Regarding the modbus watch list displaying value of 0 instead of expected 1, I checked the log and I saw a 0 saved sometime after the 1 with no source just as you have described. But the LED displaying the output of the bit on the RTU stayed lit, meaning its output has not changed. I have tested other output bits, same symptom. It happens every time. I will search for some other software to independently read the coil status of my RTU to determine where the problem lies.

2. I followed your suggestion, disable the data source before editing it. Sure enough, all ports were displayed in the Port list. I will use this work around from now on

3. Regarding browser problem, I have tested 1.8 with different browsers (FF 3.0, 3.5, IE 8) on different PCs, all with same results. Above the note, mango recognized the browser and it displayed the same version that I used on the client. If I go back to 1.7, I don't see the problem. I have also tested on 2 different servers, one running FC11 and one running CentOS 5, so it does not appear to be an issue with the server.

[mlohbihler]

Try running Firebug. Are you getting a script error on the page?