In 1994 I was called into a project for programming controllers because I knew BASIC. Things may have changed, but the commands were fairly rudimentary:

' Variables
' Analog Tattletale control
AnalogRun$ = "\8\RUN" + CHR$(13)
AnalogOn$ = "\8\GOTO200" + CHR$(13)
AnalogOff$ = "\8\11" + CHR$(13)
'AnalogPause$ = "\8\33" + CHR$(13)
AnalogResume$ = "\8\99" + CHR$(13)

We then sent these to the controller through a serial port. We ended up using QuickBASIC to write an interface for two controllers and ran it on a PC laptop. I think Perl would be an excellent tool to manipulate the strings sent to and from such a device.

Of course, I may be totally off the mark too. 8^)