Rockwell Automation 1746-BTM Barrel Temperature Control Module User Manual - Manual (Page 30)

Publication 1746-UM010B-EN-P - April 2001
3-4 Configuring the Module
Inner/Outer Zone Selection Word 1, Bit 13 for Channel 1
If you make a selection for barrel control, you also must select
whether the loop is an inner zone or outer zone.
The PID gain calculation algorithm for an inner zone is slightly
different than that for an outer zone to account for an inner zone
being more affected by adjacent zones. The inner zones are treated as
more of an integrating process than the outer zones.
If you change the inner/outer zone selection after autotune, you must
re–autotune.
ATTENTION
!
If you switch a loop between non–barrel and barrel
control, you must re–autotune the loop before
operating it. If you don’t re–autotune, the autotune
values will be wrong for the application and the
gains will be greatly distorted.
Select: for a zone: 13
inner not at either end of the
barrel 0
outer at either end of the barrel 1
Hn
H1 H2 H3
Nozzle
Zone 1 Zone 2 Zone 3
Ts Tn
T1 T2 T3 Tf
T = temperature measurement point (thermocouple)
H = heater band (element)
Typical plastic injection barrel
with multiple temperature zones
Ram
(Screw)
Outer
Zone
Outer
Zone
Inner
Zone
Inner
Zone