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Control System programming - TCP port 9001+ (TCP Proxy) OMEGA Products


This article is intended to give an overview of how we use static TCP port assignments (sometimes referred to as TCP Proxy) to communicate with Atlona switchers and connected devices. This has been implemented on many newer Atlona products including the OMEGA Family. These port assignments are fixed and are in addition to the standard TCP port that can be assigned through the web interface or API. That standard TCP port talks directly to the MCU of a device whereas the proxy ports are an open tunnel directly to a serial port (RS-232 port). These physical serial ports can be especially useful in controlling displays and sources from many manufacturers.

RS-232 Zone vs. TCP Proxy

If you have ever used standard Atlona RS-232 Zone commands, you are familiar with communicating to the serial ports. These TCP Proxy ports above 9000 replace those zone commands and send data directly to the serial (RS-232) port. Sending directly to the device simplifies the commands significantly since you don't need RS232ZoneX[command] - you just need what's in the brackets.

The first thing to know is port 9000 always talks directly to the MCU of the device at the address (e.g., you have an AT-OME-MS42 at with the TCP port set at the default of 23 - you can reach the MCU at port 23 or port 9000 when connecting to From this connection, you can use standard API commands for the device.

Beyond port 9000 we need to understand the layout since Atlona makes many switchers with varying connectivity. First, we take a look at some of Atlona's OMEGA switchers, and then we'll look at some transmitters and receivers.


On the AT-OME-MS42 shown below, we work from left to right until we get to a compatible connection. On the MS42 the first connection possible is the HDBaseT OUT. What this means is that we can communicate directly with a device, connected to the serial port, of a compatible RX, connected to that HDBaseT OUT port (e.g., a display connected to the serial (RS232) port of an AT-OME-EX-RX) if we connect via TCP to port 9001 at the switchers IP address. That's a mouthful!


We keep incrementing from left to right until all the compatible ports are accounted for. The AT-OME-MS42 only has two compatible ports, the HDBaseT port (since the RX unit has a serial port) and the RS232 console port of the MS42 itself (note: the display control protocol must be set to RS-232 on the MS42 for that local port to work).


Next, we will look at a product with much more connectivity - the Atlona AT-OME-PS62 switcher.


This switcher has more connectivity but follows the same left to right rules as before. The first compatible port is the first HDBaseT input, which means we can talk to the serial port of a compatible HDBaseT TX unit at port 9001 (switcher IP address). This follows on to port 9002 for the next HDBaseT input, and then port 9003 for the HDBaseT output.

NOTE: Port 9004 for the serial connection of the PS62 will be implemented in a future firmware release.



The AT-OME-SW21-TX-WPC is the first and currently only transmitter in Atlona's product line to support TCP Proxy. The AT-OME-SW21-TX-WPC only has a single TCP Proxy port (HDBaseT OUT - 9001). We recommend pairing this transmitter with the AT-OME-EX-RX receiver to communicate with RS232 devices using the physical serial port on the receiver. This will allow your control system to communicate with RS232 devices using a TCP connection to the transmitter. 



The AT-OME-SR21 follows the left to right nomenclature found on our OMEGA switchers. The first port HDBaseT IN will be assigned to Port 9001 while local RS232 port 1 will be assigned to Port 9002. 




If you're thinking the AT-OME-RX21 looks exactly like the AT-OME-SR21, you'd be correct. The AT-OME-RX21 just removes the USB over HDBaseT functionality. The TCP Proxy ports are exactly the same as the AT-OME-SR21




The AT-OME-RX31 adds in an additional HDBaseT Input. This means that HDBaseT IN 1 will be Port 9001, HDBaseT IN 2 will be Port 9002, and the local RS232 port 1 will be Port 9003. 




The AT-OME-ST31A has an HDBaseT output at port 9001, along with a local RS-232 out at 9002.st31a.png




We hope this improves your understanding of how to determine what port number to use for control of equipment connected to the serial port of an Atlona switcher, or a source at a TX, and/or display at an RX. Please check the product manuals for additional details on commands, baud rates, and all the other information relevant to serial control.

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