Micromod MOD: Modcell 2050R Users Guide - Manual (Page 182)

IB-23C650
RAMP/SOAK OPERATION
manual set-point is not at the same value as the ramp/soak profile set-point
(the ramp/soak profile is paused at its current set-point value when the
controller is put in manual). The switch back to automatic causes the process
variable to be under automatic control in response to the ramp/soak set-point.
Auto/Manual Transfer with Set-Point Tracking
If the controller has been configured for set-point tracking, the set-point tracks
the process value when the controller is in manual. When a transfer to
automatic is made, the process may not be at the ramp/soak set-point. If the
profile is already running or the tracked set-point is within the ramp/soak set-
point hysteresis, a set-point bump will occur. If the profile is waiting to start
because the process is not within the ramp/soak set-point hysteresis, then the
set-point will stay at the tracked set-point and the set-point must be moved
(use the hold feature) to within ramp/soak set-point hysteresis for the profile to
begin.
Auto/Manual Transfer without Set-Point Tracking
If the controller does not have set-point tracking, the set-point and process
may not be together at the time of transfer from manual to automatic. Again,
the transfer will cause a bump. The response following the transfer depends
on the controller configuration. If the controller has integral response, the
process will ramp to the set-point at the reset rate. If the controller does not
have integral, the set-point/ process deviation at the time of transfer will be
maintained. This deviation can be eliminated by returning to manual, adjusting
output to eliminate the deviation, and switching back to automatic.
Auto/Manual Transfer for On/Off Control
If the controller is set up for on-off control, the bumpless transfer feature does
not apply when switching from automatic to manual. When switched to
manual, the on-off controller output is always initialized at 0% when switched.
Operation in manual is the same as for a time proportioning controller. When
switching from manual back to automatic, operation is the same as for all other
types of control as described in the operations section.
OPERATION IN MANUAL
When the controller is switched to manual, the first display seen is
process/output. Output can be adjusted using the up and down keys. The
scrolling sequence is the same as for the automatic mode. The ramp /soak
profile does not run in manual.
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