Feasibility to connect and access multiple rs232 data feeds via TCP

Using Arduino Project Guidance
1

I currently have a non-Arduino, wifi based system that I would like to explore the feasibility of redesigning as an Arduino solution and am looking for input on this.
I currently have a collection of 10 monitoring locations. Each location has a single rs232 sensor that is connected to a single wifi rs232 serial port. I have a logging PC that connects to each rs232 sensor via tcp/ip address and port number and collects and massages the data streams. Back on my laptop I am using a windows-based TCP/IP datalogger. The logging and data manipulation on the PC is all working fine for now.

My problem is that I want to now expand each location with additional rs232 sensors. With my current setup I can't do this without adding adding additional wifi rs 232 modules (1 wifi rs232 module costs about as much as 3 Arduinos)
For now, what I would like to do is connect the rs232 sensors (2 of them) to a single Arduino at each location and let the Arduino facilitate the wireless transfer of the rs232 data back to the logging pc. I also want to switch from a wifi network to one utilizing xbee mesh radios due to the logisitics of the application area. The path of least resistance for me is to get each sensor to be "visible" back to the logging PC as an ip:port address like I am currently using: i.e.: 192.168.1.21:2000

particulars:
each sensor is a simple unidirectional data stream.
each sensor is a 2 wire rs232 connection (Tx and ground)
I presume I would need some sort of tool/code that would allow me to redirect each rs232 port to tcp port. (currently each monitor I have has a static IP assigned so the logger on the PC side knows where to find it via an IP and port.)
I found the Arduino Mega 2560 with 4 serial ports so I assume this is the Arduino board I would want to utilize.

So in general is this feasible or are there suggestions on a better way to do this?
If it is, some direction of what I would need to obtain or develop would be great.

Would really appreciate any input.
Cheers!
Darren

2

Normally, to connect an RS232 serial device to TTL serial device such as an Arduino you'd need a TTL-to-RS232 converter. In this case, since the devices are send-only, it may be possible to build a DIY converter using a simple transistor.

If it was acceptable to use one XBee per sensor, your remote device could consist of the sensor, something to convert RS232 to TTL, and an XBee to transfer the serial stream wirelessly back to your central unit - I don't think you'd need an Arduino at all.

If you want to use the Arduino as a concentrator, you'd need to have several serial inputs (each converted from RS232 to TTL) which implies either using one of the bigger Arduinos with more hardware serial ports, or using the AltSoftSerial library. You'd also need to connect the XBee to the Arduino, perhaps via an XBee shield. You can see the cost and complexity mounting up, and if the reason for using concentrators is to reduce costs, it might turn out not to be any cheaper.

I don't know whether it would cope with your environment, but you might consider using something like this:

http://shop.ciseco.co.uk/rf-328-bare-arduino-atmega-328-compatible-micro-board-rfu-328/

I don't see the range mentioned, but I seem to remember reading that it was in the range of tens of yards which is presumably comparable to your existing WiFi. Given the price, you might want to have a play with one of these and see whether it looks viable.