Emerson iPro, Installation And Operation Manual

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28 • iPro Case Controller I&O Manual FM V1.01 026-1738 Rev 1
information from the slave controllers is shared with the master
over this connection. The master case controller regulates the
EEPR to maintain the case temperatures to the target setpoint. The

maximum number of case controllers in a lineup is six (6), where
one of the six (6) is the master controller. The EEPR regulation
can be done based on the average, minimum or maximum case

local temperature where local means the discharge air sensors
connected to the master controller only. The EEPR regulation can
also be done based on the average, minimum or maximum lineup
temperature where lineup means all the case controllers connected
to the RS485 slave network. The selection is done through the

parameter SSCP.
10.3.4.1. Superheat and Suction Control

Mode-PID
The EEPR valve regulation is accomplished by comparing
control value to the target setpoint and determining a PID output
value for the position of the EEPR valve. The PID control can be
put into Manual or Automatic mode by setting the
P value. When
the P value is set to 0 , the application will automatically adjust
the proportional band value to find the best stable value for
regulation.