Rockwell Automation 1395 Digital DC Drive FRN 5-10.10/9.30 - Manual (Page 195)

Chapter 7
Programming Parameters
7-29
Parameter 152 – Logic Command 3 [Logic Cmd 3]
Internal units : None
Programming Terminal units: Bit Field
Description : This controls Drive logic operation when the
Programming Terminal is in control of the Drive. All functions
present in Logic Command 3 are identical to Logic Command 1. The
Command/Enable bit in logic command 3 will select Drive control
with logic command 3 (if set) regardless of the state of the
Command/Enable bit in other logic words. The Stop bit in logic
command word 3 is logically OR’D with the Stop bits in logic
command word 1 and 2.
Parameter 153 – Velocity Reference Fraction [Vel Ref Fraction]
Internal units : 65535 = ffffh = base motor speed / 4096
Programming Terminal units: None
Description : This word supplies the fractional part of an external
velocity reference when external velocity control has been selected in
the Logic Command word. The data contained in this word
represents the low order, fractional portion of a 32 bit velocity
reference.
The motor base speed value is always equated to the following
number representation:
Parameter 153 Parameter 154
+/– 4,096 0
Use of this parameter allows extended resolution when specifying an
external velocity reference. Note that a value of 32768 (8000h) is
equivalent to 1/2 of 1 unit of reference in Parameter 154. Similarly,
16384 (4000h) is equivalent to 1/4 of 1 unit of reference, and 65535
(ffffh) is equivalent to 65535/65536 or 1 unit of reference. In this
way, Parameter 153 can be thought of as a means of specifying an
additional fraction of one unit of velocity reference for Parameter
154. If fraction resolution is not needed, then Parameter 153 should
not be linked and its value will be defaulted to zero.
Parameter 154 – Velocity Reference Whole [Vel Ref Whole]
Internal units : 4096 = 1000h = 1 pu = base motor speed
Programming Terminal units: RPM
Description : This word supplies the whole number part of an
external velocity reference when external velocity control has been
selected in the Logic Command word. The data contained in this
word represents the high order, whole number portion of a 32 bit
velocity reference.