Rockwell Automation 1771-QC , D17716.5.25 SER/B SERVO POS User Manual

Page 138

Formatting and Interpreting Data Blocks

Chapter 7

7Ć56

Figure 7.36

Position/DwellĆtime Words

07 06 05 04 03 02 01 00

Sign:

0 = +

1 = -

inch

metric/

17 16 15 14 13 12 11 10

BCD home position value

(999.9999 inches or 19999.999

mm max or dwell time value 9999.999

s max)

Most significant digits

Least significant digits

11020

0 = absolute

1 = incremental

Most Significant Position Word

Least Significant Position Word

seconds

For dwell values, these words express a 7-digit number in BCD format.
The maximum programmable value is 9999.99 seconds. The minimum
programmable value is 0000.020 seconds.

For inch values, these words express a 7-digit number in BCD format.
The maximum programmable value is 999.9999 inches. If bit 14 of the
most significant position word is on when the SMCW is programmed for
inch units, the status block indicates a programming error to inform the
operator that a position value greater than 999.9999 inches has been
programmed.

For metric values, these words express an 8-digit number in BCD format.
The maximum programmable value is 19999.999 mm.

For position values, use bit 15 of the most significant position word to
specify the positioning mode:

Absolute - If you turn off this bit, the position value is an axis position

coordinate relative to the zero position of the axis. For example, if the
axis is at position coordinate +4.5 and the position words call for
motion to absolute endpoint +3.5, the servo positioning assembly