Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Turbo PMAC Computational Features
243
Value Assignment
Values assigned to an I-variable may be either a constant or an expression. The commands to do this are
on-line (immediate) if no buffer is open when sent, or buffered program commands if a buffer is open.
Examples:
on-line (immediate) if no buffer is open when sent, or buffered program commands if a buffer is open.
Examples:
I120=45
I120=I120+5
I(P1*100+20)=10
Limited Range
For I-variables with limited range, an attempt to assign an out-of-range value does not cause an error.
The value is automatically rolled over to within the range by modulo arithmetic (truncation). For
example, I3 has a range of 0 to 3 (4 possible values). The command I3=5 would assign a value of (5
modulo 4) = 1 to the variable.
The value is automatically rolled over to within the range by modulo arithmetic (truncation). For
example, I3 has a range of 0 to 3 (4 possible values). The command I3=5 would assign a value of (5
modulo 4) = 1 to the variable.
Non-Volatile Storage
When a value is assigned to an I-variable, the value in an active memory register that is volatile (does not
retain its value when power is removed) is being removed. Copy all of these active values to non-volatile
flash memory with the SAVE command. On a power-up or reset, the last values saved into flash memory
are copied back into active memory automatically for use.
retain its value when power is removed) is being removed. Copy all of these active values to non-volatile
flash memory with the SAVE command. On a power-up or reset, the last values saved into flash memory
are copied back into active memory automatically for use.
Default Values
Default values for all I-variables are contained in the manufacturer-supplied firmware. They can be used
individually with the I{constant}=* command, or in a range with the
I{constant}..{constant}=* command. Upon board re-initialization by the $$$*** command
or by a reset with the re-initialization jumper in the non-default setting, all default settings are copied
from the firmware into active memory. The last saved values are not lost; they are just not used.
See the I-variable description section for the functions of individual variables.
individually with the I{constant}=* command, or in a range with the
I{constant}..{constant}=* command. Upon board re-initialization by the $$$*** command
or by a reset with the re-initialization jumper in the non-default setting, all default settings are copied
from the firmware into active memory. The last saved values are not lost; they are just not used.
See the I-variable description section for the functions of individual variables.
P-Variables
P-variables are general-purpose user variables. They are 48-bit floating-point variables at fixed locations
in Turbo PMAC’s memory, but with no pre-defined use. There are 8192 P-variables, from P0 to P8191.
A given P-variable means the same thing from any context within the card; all coordinate systems have
access to all P-variables (contrast Q-variables, which are coupled to a given coordinate system, below).
This allows for useful information passing between different coordinate systems. P-variables can be used
in programs for any purpose desired: positions, distances, velocities, times, modes, angles, intermediate
calculations, etc.
in Turbo PMAC’s memory, but with no pre-defined use. There are 8192 P-variables, from P0 to P8191.
A given P-variable means the same thing from any context within the card; all coordinate systems have
access to all P-variables (contrast Q-variables, which are coupled to a given coordinate system, below).
This allows for useful information passing between different coordinate systems. P-variables can be used
in programs for any purpose desired: positions, distances, velocities, times, modes, angles, intermediate
calculations, etc.
Type of Memory Used
P-variables can be located in either the main memory, or in the supplemental battery-backed parameter
memory (if Option 16 is ordered). If I46 is set to 0 (default) or 2, the P-variables are located in the main
memory, which has fast access (1 wait state) but whose values are not retained without a SAVE command
copying the values to flash memory. On power-up/reset, the last saved values are copied from flash
memory into the active variable registers in RAM.
memory (if Option 16 is ordered). If I46 is set to 0 (default) or 2, the P-variables are located in the main
memory, which has fast access (1 wait state) but whose values are not retained without a SAVE command
copying the values to flash memory. On power-up/reset, the last saved values are copied from flash
memory into the active variable registers in RAM.
If I46 is set to 1 or 3, the P-variables are located in the Option 16 battery-backed RAM, which has slow
access (9 wait states) but whose values are retained automatically by the battery when power is removed.
access (9 wait states) but whose values are retained automatically by the battery when power is removed.
Special-Use P-Variables
Generally, Turbo PMAC firmware has no automatic use of P-variables. However, it can make special use
of variables P0 – P32 and P101 – P132, as described below.
of variables P0 – P32 and P101 – P132, as described below.