Reference Manual

16-Axis MACRO CPU Software Reference Manual
16-Axis MACRO Station MI-Variable Reference 17
$Dx 3 Exponential filter of parallel data Max Change per Cycle Filter Gain (Inverse
Time Constant)
$Ex 1 Sum or difference of entries - -
$Fx 3 High-resolution Interpolator Address of 1
st
A/D
converter
A/D Bias Term
Digital Incremental Encoder Entries ($0x, $Cx): These two conversion table methods utilize the
incremental encoder registers in the DSPGATE ASICs on the Station. Each method provides a processed
result with the units of (1/32) count – the low five bits are fractional data.
With the $0x method, the fractional data is computed by dividing the Time Since Last Count register by
the Time Between Last Two Counts register. This technique is known as 1/T extension, and is the most
commonly used method. It can be used with a digital incremental encoder connected directly to the
Station
With the $Cx method, the fractional data is always set to zero, which means there is no extension of the
incremental encoder count. This setting is used mainly to verify the effect of one of the 1/T extension, or
the parallel extension of an analog encoder, explained below.
The ‘x’ in the second digit is always 0 in both of these methods.
With either of these conversion methods, the source address in the low 16 bits is that of the starting
register of the machine interface channel. The addresses of the machine interface channels that can be
used, and the ECT entry MI-variables that correspond to them, are shown in the following tables. The
‘m’ is the conversion method, representing ‘0’ (Incremental Encoder-1/T interpolation extension) or ‘C’
(Incremental Encoder-no extension).
Entries for Backplane Axis Boards (ACC-24E2x)
Machine
Interface
Channel #
16-Axis
MACRO
Station Base
Address
Conversion
Table Entry
Machine
Interface
Channel #
16-Axis
MACRO
Station Base
Address
Conversion
Table Entry
1 $8000 $m08000 9 $9000 $m09000
2 $8008 $m08008 10 $9008 $m09008
3 $8010 $m08010 11 $9010 $m09010
4 $8018 $m08018 12 $9018 $m09018
5 $8040 $m08040 13 $9040 $m09040
6 $8048 $m08048 14 $9048 $m09048
7 $8050 $m08050 15 $9050 $m09050
8 $8058 $m08058 16 $9058 $m09058
These are single-line entries in the table, so the next line (MI-Variable) is the start of the next entry.
Analog Incremental Encoder Entries ($8x, $Fx): These two entries process data from analog sinewave
encoders through a Delta Tau interpolator, providing a high number of position states per line using
fractional count data.
Low Resolution: With the $8x method, the fractional data is computed by reading the five inputs at bits
19-23 of the specified address (USER, W, V, U, and T flag inputs, respectively). This technique is
known as parallel extension and can be used with an analog incremental encoder processed through
accessories for the older Macro Stack Technology. This entry will not be utilized very often since the 16-
Axis Macro Station is used in backplane mode only.