Indirect Variables

Note  This section applies only to NI 73xx motion controllers.

If you make the read or load functions point to variables 0x81 to 0xF8, the functions use the value loaded in variables 1 to 0x78 and interpret them as the address where the value is read or loaded. This creates two levels of indirection.

Making the return vector of the Read Position VI or function point to 0x81 causes the position to end up in the address contained in onboard variable 1, as shown.

Using indirect variables can be very useful in looping in onboard programs, as well as dynamically changing the input values to functions.