control serial port with php?

Is is possible to send commands and receive feedback via a serial port using php? I've got an antenna controller hooked to a PC that is capable of communicating this way and want to do it by web interface. I've found a couple threads that touch on the topic but most say "use another language". Thanks.

if your "antenna controller" is using ascii control commands over the serial line and you are on unix, you can fopen() your /dev/cua device and read/write to it.
but many devices encode their commands with using the serial control lines, i doubt this is possible in PHP without external programs...
do you have some more info about the protocol being used?

Hello M. Hirsch, thanks for the reply, and apologies for the belated follow-up. The documentation for the "controller" states that it conforms to the "SA Bus protocol originally defined by Scientific Atlanta." An example of a response from the device is:

byte 0: ACK
byte 1: A (where A is the address of the controller)
byte 2: 'CC' (the command code of the msg which triggered the reply)
byte3: 'F' (Ascii 'F', for offline)
byte 4: ETX

So it looks to me like it is using ascii control commands, correct? I'll pursue the fopen() method that you pointed out.