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Showing results for tags 'rs485'.
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4felo posted a topic in ModbusFinally got multiple arduino slaves being monitored and controlled by Daqfactory. I've been working on this for the past 2 weeks and found no documentation available. I'm able to read analog inputs registers, write to and monitor PWMs registers, read & write to digital pin registers. Communication is through two wire modbus RTU. It's simply fascinating, i can literally monitor an control any of my inputs/outs in real time using cheap arduino unos. Stuff that is done by some really expensive PLCs out there. I'm still making some documentation, but if any of you need assistance post in the forum.
I have just started using DAQFactory and now DAQFactory Express (both Release 17.1 Build 2309) for monitoring a temperature controller via RS485/Modbus. I am impressed with DAQFactory (thanks to the developers for such a great product) and am slowly getting an understanding of how to use it after lots of attempts, reading and searching of the forum. I have been able to configure a new RS485/Modbus device in DAQFactory and successfully connect using a USB-Serial adapter to a Shimaden SRS11A temperature controller and retrieve the current temperature value. I have also configured a single channel and a logging set which work well. I am trying to add some error handling to manage serial port errors on the RS485/Modbus connection such as when the RS485/Modbus device is powered off, the USB-Serial adapter is not plugged into the computer, or a RS485/Modbus timeout. I am using the OnAlert() function to deal with these types of errors as they are not caught by using the Try/Catch approach in scripts/sequences. This is catching errors/alerts OK except I am observing inconsistent behaviour. I have an auto-start sequence called Main which sets the Channel timing to zero then does a device...initcomm() to see if communication is working. When I setup a test scenario where the USB-serial adapter is connected but the RS485/Modbus device is powered off, I sometimes get a timeout error, no error or an occasional error where DAQFactory cannot load the driver TriLogi.dll (I am not using this driver, my device is using the supplied ModbusRTU one). The fault is probably something I have or haven't done but I was wondering whether anyone has seen something like this before? Any help or suggestions are welcome. Thanks Paul
Hi, What is the best way to test connectivity of RS485 and TCP devices ? I want to test devices and if connection fails (like wire broken, radio connection lost etc ) device will be on alarm list..? I guess that result can be added to virtual channel like 0 or 1 for each device ??