Connecting to Realand AC 121 for Remote Data Download via internet

I thought of putting this article as you might also come across similar issues, also trust me on this, up to the date, until I uploaded this blog post, myself or any one of my team mates couldn’t find a single article about solving the data download from AC121 through internet. Even the AC 121 manual couldn’t do much for us.

The problem

AC 121 was fixed at a client site in location X and the Cyber Concepts Time Attendance software was installed at the HQ of the same client. There was only a network cable connected to the Realand AC 121 and there was no computer on site which could connect to the AC 121 Biometric device to download attendance data.

Since i have configured few types of biometric scanner devices with our Time and Attendance solution, I thought AC 121 would be another walk in the park.

Sadly it was not. Even though I tried all possible configurations, the pc on the HQ was not even able to connect to the biometric device.

Since the usual setup did not work I had to go to the drawing board.

Going back to the drawing board

Going through what you have already done, up to now always lead you to a solution at least in this case a lead to a path to a solution.

Here is my check list

The biometric scanner’s IP, Gateway, subnet and DNS should be in line with the router or the network’s IP configuration, in my case below were the settings
IP :

Gateway :

Subnet :


Router port forwarding should be done correctly; in this case I opened the 5500 port both internally and externally. In my case it was a Dlink DSL-2750U router. As this is so important, I request you to go through your specific router’s manual to find out how to do the port forwarding correctly
If all the above are correct, I got the Granding 3000TC biometric scanner device (this is also another device we Cyber Concepts has implemented successfully at many clients), set up the same IP settings as AC121 and checked if the port forwarding works for sure. Yes, it worked and my colleague at the client’s HQ was able to connect to the machine.

Check for any additional settings you missed last time

In my case, yes, I’ve found a setting which previously I thought useless which is the RT PUSH on the communications menu of the AC 121
Also keep in mind that DHCP should be always set to NO, as if this is active the device will not let you enter any network settings.


I went through the RT PUSH menu; it had RS234, UDP and NO as options. Since we had nothing to do with RS234 and it was already set in as NO, I went with UDP, without changing anything and ONLY doing what I mentioned above, I tried to connect to the machine from the HQ, still nothing.

It hit me at this point since the RT PUSH was set to UDP; it was a no brainer that the port forwarding record should be changed to UDP protocol as well.

What a relief!!, it connected beautifully,

A special thank you goes out to Tharindu and Jayan for being aside me and helping me out,

Thanks guys

Share your story about AC 121 with us, all your comments and suggestions are welcome, also comment below if you have any questions