About the HAI product, I've never worked with it, but I'm pretty sure I've seen a picture where there was a RFX9400/9600 option.

It’s simply looking at the data section of the ethernet frame in wireshark. You can send you’re own UDP packets with Com Operator Pal or UDP test tool.

Sending RS232:
 
header:
3 bytes to indicate message number (00 00 01)
1 byte statuscode (00 = Request, 20 = Ok, 24 = Failed, 40 = Finished)
1 byte repeatcount (00)
7 bytes probably reserved (00 00 00 00 00 00 00)
 
data:
1 double byte to indicate action
  00 = Completed
  30 = Requeststatus
  31 = Repeat last frame
  40 = IR
  50 = RS232
  63 = SetRelayState
  64 = ToggleRelayState
  65 = GetRelayState

1 byte  ??? (02) (maybe Pronto major version 2.00?)
1 byte  ??? (00) (maybe Pronto major version 2.00?)
1 byte  datalength (from action to end data)
1 byte 
  first part RS232 port
  port1 = 0
  port2 = 1
  port3 = 2
  port4 = 3

  second part  RS232 baudrate
  2400   = 2
  4800   = 3
  9600   = 4
  14400  = 5
  19200  = 6
  28800  = 7
  31250  = 8
  38400  = 9
  57600  = a
  115200 = b

1 byte combined rs232 flags
  Stopbits:
  1   = 0
  1.5 = 2
  2   = 4
  Parity:
  none  =  0
  even  =  8
  odd   =  16
  mark  =  24
  space =  32
  Databits:
  5 = 0
  6 = 64
  7 = 128
  8 = 192
  So, Stopbits 8 + Parity space + Databits 8 = 226 = e4

2 bytes Duration in ms (01 ea = 1ea = 490ms = .49s)
7 bytes probably reserved (00 00 00 00 00 00 00)
1 byte  rs232 repeatcount (01)
? bytes RS232 string
 
end data:
3 bytes to indicate end or reserved (00 00 00)

It's possible to send multiple data + end data (multiple commands) in one packet.