Watlow Series D8 - Manual (Page 115)

Series D8 User’s Guide Chapter 4: Operation and Setup
Doc. 0600-3120-2000 Watlow Anafaze 97
set separate high and low deviation values at the HiDeviation
value
and LoDeviation value parameters in the Alarms menu.
Upon power up or when the set point changes, the behavior of
the deviation alarms depends upon the alarm function:
•
If the alarm function parameter is set to standard, then
deviation alarms do not activate until the after the pro-
cess variable has first come within the deviation alarm
band. This prevents nuisance alarms.
• If the alarm function parameter is set to boost, then the
deviation output switches on whenever the set point and
process variable differ by more than the deviation set-
ting, regardless of whether the process variable has been
within the deviation band. This allows you to use boost
control upon power up and set point changes.
Global Alarm
The D8 comes equipped with a global alarm output. The glo-
bal output is activated if one or more of the following condi-
tions occurs:
•
A system alarm occurs, or
• A failed sensor alarm occurs and is unacknowledged, or
• A process alarm occurs and is unacknowledged. The glo-
bal alarm occurs only if the alarm function is set to stan-
dard
in the Alarms menu. (The global alarm does not
occur if the alarm function is set to boost.)
The global alarm output stays active until all alarms have been
acknowledged.
When the global alarm output is active, it conducts current to
the controller’s dc common. When the global alarm output is
not active, it does not conduct current.
NOTE! You cannot configure any parameters for the
global alarm. The active state of the global
alarm output is NOT affected by the D/O
alarm polarity parameter in the Global setup
menu.
Setting Up Process Variable Retransmit
The process variable retransmit feature retransmits the pro-
cess variable of one loop (primary) via the control output of
another loop (secondary). This signal is linear and proportion-
al to the engineering units of the primary loop input.