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rantingmoon

Modbus Tcp Port 502 Won't Connect

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Can someone please help me?

I've set up my modbus devices and they are just either connecting or disconnecting.

I checked port 502 and find out that it's not open, so assuming that it's because of that. So I tried opening port 502, allowing it on the firewall both inbound and outbound rules, but when i check for the listening port it still not there.

I also tried to port forward it on the router but still doesn't work.

It's frustrating :|

Is there any other way I can open this port?

Please help! Thank you so much!

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I don't understand what you are trying to do. You have a Modbus device on port 502 (the standard port) that is outside your network and you are trying to connect to it from DAQFactory? Or is the Modbus device inside your network and you are trying to connect to it from outside? Personally, I'd start with everything on a single network and make sure it all works, then figure out how to get it through any firewall. Then you know the issue is with the firewall settings.

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It sounds like you are trying to connect from to a modbusTCP device outside the network your DAQFactory system is on. It is not clear what you’re doing, but trying to connect modbusTCP through a firewall is likely going to give you problems. ModbusTCP is pretty touchy without trying to tunnel through a network, you will likely get lots of timouts and communications issues between DF and the modbusTCP device.

If you want to remotely monitor the device, I highly recommend looking into DAQConnect. I have used it for some time, its very solid. If your remote device need be connected, please check out the DAQBBridge for Modbus. I have not installed a DAQBridge, but its a lot less expensive than installing a remote computer with DF. Check out: https://www.daqconnect.com/daq/company/daqbridge.html

I hope this helps.

-Greg

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