Delta Tau GEO BRICK LV User Manual

Executive Program Setup Menu 

Generally, the setup of the encoder conversion table I-variables can be done interactively through the 
configuration menu in the PMAC Executive Program.  The following section explains how the setup can 
be done directly and “manually.” 

Entry First Setup I-Variable 

The first setup I-variable for an entry has three parts: the conversion method, a mode-switch bit, and the 
address of the source data.  The conversion method, which determines what processing is to be done, is 
contained in the first hex digit (bits 20 – 23).  The mode-switch bit, which specifies variants to the 
processing, is contained in bit 19.  The source address, which specifies which register or set of registers 
contains the raw data, is contained in bits 0 – 18. 

The following table shows how the first I-variable for an entry is structured: 

Bit 

23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Digit 

  1    2    3    4    5    6  

Contents Method 

* 

Source 

Address 

For example, the parallel extension (method digit $8) of an incremental encoder from a PMAC-style 
(mode-switch bit 0) Servo IC 0 Channel 1 (source address $078000) in the first setup line of the 
conversion table would be: 

The same parallel extension (method digit $8, but from a PMAC2-style (mode-switch bit 1) Servo IC 0 
Channel 1 (source address $078000) in the first setup line of the conversion table would be: 

The structures of any subsequent lines for an entry are dependent on the method; each type is discussed 
below. 
The following table summarizes the operation specified by each method digit. 

$0 1 

1/T 

Extension 

of 

Incremental Encoder 

None - 

- 

$1 

1 

Acc-28 style A/D 
converter (high 16 bits, 
no rollover) 

0 = signed data 
1 = unsigned data 

- - 

$2 

2 

Parallel Y-word data, no 
filtering 

0 = normal shift 
1 = unshifted 

Width/Offset Word 

- 

$3 3 

Parallel 

Y-word 

data, 

with filtering 

0 = normal shift 
1 = unshifted 

Width/Offset Word 

Max Change per Cycle 

$4 

2 

Time Base scaled digital 
differentiation 

None 

Time Base Scale Factor 

- 

$5 

2 

Integrated Acc-28 style 
A/D converter 

0 = signed data 
1 = unsigned data 

Input Bias 

- 

$6 2 

Parallel 

Y/X-word 

data, 

no filtering 

0 = normal shift 
1 = unshifted 

Width/Offset Word 

- 

$7 3 

Parallel 

Y/X-word 

data, 

with filtering 

0 = normal shift 
1 = unshifted 

Width/Offset Word 

Max Change per Cycle 

$8 1 

Parallel 

Extension 

of 

Incremental Encoder 

0 = PMAC IC 
1 = PMAC2 IC 

- - 

$9 

2 

Triggered Time Base, 
frozen 

0 = PMAC IC 
1 = PMAC2 IC 

Time Base Scale Factor 

-