Serial connection: Used straight-through RJ11 (6-cond).  
IP (XM-OCTAL) jumpers default.

RJ-11 recepticle (taper at bottom)
| | | | | |
1 2 3 4 5 6

1,2 = RxD (to db9 pin 3)
3,4 = GND (to db9 pin 5)
5,6 = TxD (to db9 pin 2)

Enter PID parameters as strings.  This helps reduce the serial port
traffic by limiting the number of zeros that get sent out.  When I tried
using doubles for inputs, the STR(X) function created numbers with many
zeros after the decimal point.  

Because of this, was able to add PID query to PID setting commands.