Refrigeration Control Modes Software Overview • 27
Note that if the Modbus address or baud rate is changed, the controller must be rebooted.
To configure the controller as a slave case controller in Suction mode, the following parameters must be set:
Note that if the Modbus address or baud rate is changed, the controller must be rebooted
.
10.3.3.3. Suction Mode-Refrigeration Relay
Control
In Suction mode, the refrigeration relay is controlled based on the
selection of the parameter SSCP. The control value is used with
the case target setpoint and deadband. The control temperature
sensors include the master controllers connected sensors as well
as all online slave controller sensors in the lineup. If the calculated
control temperature is greater than the setpoint, the refrigeration
relay is on. If the control temperature is less than the setpoint plus
the deadband, the refrigeration relay is off (entire deadband is
applied below the setpoint). The refrigeration relay is set to OFF
during defrost.
10.3.4. Superheat and Suction Control
Mode
Selecting the Superheat and Suction control mode can be done by
setting parameter CRE=Superheat and Suction. This mode is
designed to manage one EEPR, one LLSV, and up to three EEV
in one case. When a lineup of cases is present with EEV valves
and there is one EEPR for the lineup, this mode must be selected
on the master controller of the lineup, which is the controller that
the EEPR is connected to. This mode manages the EEPR for the
circuit and its own locally connected EEVs. Case controllers in
this mode are designated as either master controllers or slave
controllers, with the master controller regulating EEPR and liquid
line solenoid valve for the refrigeration circuit lineup. The slave
case controllers communicate with the master controller through
the RS485 slave port on each device. Case temperature
S3Addr Modbus address of slave device 3 4 if 3 slave CC are present; otherwise set at 0
S4Addr Modbus address of slave device 4 5 if 4 slave CC are present; otherwise set at 0
S5Addr Modbus address of slave device 5 6 if 5 slave CC are present; otherwise set at 0
Modbus_Addr Modbus address of this controller 1
Baud Baud of Modbus communication 19200
Parameter Description Parameter Value for Master
Controller
CrE Control Type Suction
SSCP Superheat and suction control probe selection User choice, Average Lineup
Recommended
EEV EEV driver Not Present
EEVCnt Number of EEVs in the case 0
StandaloneCC Yes = Controller is standalone (no lineup)
No = Controller is a master or slave in a lineup
NO
XEV20D-1 V1 Valve assigned to XEV20-1 valve output 1 No Valve
S1Addr Modbus address of slave device 1 0
S2Addr Modbus address of slave device 2 0
S3Addr Modbus address of slave device 3 0
S4Addr Modbus address of slave device 4 0
S5Addr Modbus address of slave device 5 0
Modbus_Addr Modbus address of this controller
Set based on the S1-S5Addr of the master CC
Baud Baud of Modbus communication 19200
Table 10-3 - Slave Controller Configurations for Suction Control Mode
Table 10-2 - Master Controller Configurations for Suction Control Mode
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