Rockwell Automation 1771-QC , D17716.5.25 SER/B SERVO POS - Manual (Page 117)

Formatting and Interpreting Data Blocks
Chapter 7
7Ć35
Figure 7.24
Deceleration Step Rate Word
17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
Decel Step Rate
Word 20 (Axis 1)
Word 39 (Axis 2)
Word 58 (Axis 3)
Multiplier
001 = x 10 -1
000 = x 10 0
010 = x 10
100 = x 10
110 = x 10
111 = x 10
1
2
3
4
inch metric
This BCD value (0.999 ipm or
19.99 mmpm max) times the
multiplier is the decel step rate.
During deceleration, the axis feed
rate steps directly to zero once the
rate drops to this level. This only
applies to jog and search home.
11046
decimal
point
decimal
point
Software Travel Limits
Words 21 and 22 (40 and 41, 59 and 60) specify the axis position values
of the axis software travel limits (Figure 7.25). When a programmed
move calls for the axis to move beyond a software travel limit, if there is
time, the servo positioning assembly automatically decelerates the axis at
the programmed rate for the current move so that it stops at or before the
software travel limit position.
If there is no time to decelerate the axis before the limit is exceeded, the
servo positioning assembly executes an immediate stop. This could occur
following a continuous move because the next move starts with the
feedrate of the previous move rather than zero.
Software travel limit values are axis position values. Note that if zero is
the programmed travel limit value, there is no software travel limit. The
absolute positions of the software travel limit vary with changes in axis
position value due to preset or home commands. In addition to the
software travel limit you must have extreme axis overtravel limit switches
wired in the master control relay circuit.