Preferred FlexFit 110 - Page 82

4-74 Parameters
FlexFit – Linkageless Control – Revision 1.0
PREFERRED
UTILITIES MFG CORPORATION
PP
AA
RR
AA
MM
EE
TT
EE
RR
SS
Setting a negative number here sets the start point above the setpoint. (I.e., set this parameter to a negative number,
if you want the boiler cycle to start before the pressure or temperature drops below the setpoint).
Error Check P3.4.3 + P3.4.2 must be greater than 0.
P3.4.3 cFh StoP deVIatIon
Menu > Optional Features > Local/Remote Mode Password Level: Operator Restricted? No
This determines the amount of deviation from setpoint needed to stop a Call for Heat (CFH) sequence.
Options: 0.1 to 500.0 [Default 10.0]
The boiler stops when the boiler outlet rises above the current setpoint by this amount for more than 2 seconds.
Setting a negative number here sets the stop point below the setpoint. (I.e., set this parameter to a negative number,
if you want the boiler cycle to stop before pressure or temperature rises above the setpoint).
Error Check P3.4.3 + P3.4.2 must be greater than 0.
P3.4.4 enable reMote Mode
Menu > Optional Features > Local/Remote Mode Password Level: Technician Restricted? No
Determines if the FlexFit can accept a ring rate signal from a remote location.
Options: Disabled: Local mode only – remote mode cannot be selected.
Enabled: Remote mode can be selected.
P3.4.5 cFh reMote Mode
Menu > Optional Features > Local/Remote Mode Password Level: Technician Restricted? No
Determines the FlexFit Call for Heat (CFH) logic in remote mode.
Options: CFH Terminal: CFH is based on a 120 Vdc contact closure to terminal 17.
SP Deviation: CFH is based on the boiler outlet deviation from the current setpoint. This is based on steam pressure
or water temperature.
Modbus: CFH is based on Modbus coil 000274 (or register 49539 bit 1). 1 = Start
Error Checks If "P3.1.1 Local Firing Rate Control Source" equals 135 Ohm Demand or 4-20 P7810 Demand, then "CFH Remote
Mode" cannot equal SP Deviation.
If "P3.4.6 Remote Modulation" equals 4-20 mA FR or Modbus FR, then "CFH Remote Mode" cannot equal SP
Deviation.
P3.4.6 reMote ModulatIon
Menu > Optional Features > Local/Remote Mode Password Level: Technician Restricted? Yes
Determines the modulation method used in the FlexFit during remote mode.
Options: 4-20 mA FR: The 4-20 mA signal wired to analog input terminals 112 and 113 is the ring rate. The FlexFit PID is
not controlling the ring rate. Also, see "P3.4.8 Remote Rate Cutback SP".
4-20 mA SP: The 4-20 mA signal wired to analog input terminals 112 and 113 is the ring rate PID setpoint. Setpoint
signal scaling is congured by "P3.4.9 Remote SP Span" and "P3.4.10 Remote SP Zero".
Modbus FR: Modbus register 400012 is the ring rate. The FlexFit PID is not controlling the ring rate. Also, see
"P3.4.8 Remote Rate Cutback SP".
Modbus SP: Modbus register 400048 is the ring rate PID setpoint.
Error Checks If "P3.1.1 Local Firing Rate Control Source" equals 135 Ohm Demand or 4-20 P7810 Demand, then "Remote Mod-
ulation" cannot equal 4-20 mA SP or Modbus SP.
If "P3.4.5 CFH Remote Mode" equals SP Deviation, then "Remote Modulation" cannot equal 4-20 mA FR or Modbus
FR.
P3.4.7 reMote Fault reSPonSe
Menu > Optional Features > Local/Remote Mode Password Level: Technician Restricted? No
This determines what action the FlexFit will take with a faulted/failed remote modulation signal. The "Remote Modulation" signal is
considered faulty if the 4-20 mA signal is outside -5% to 105% or if there is no Modbus activity for longer than the Modbus timeout.
See "P6.1.5 Modbus Comm Timeout (Sec)" on page 4-82.
Options: Remote: The FlexFit remains in remote even if the remote modulation signal is faulty.
Local: The FlexFit automatically switches to local if the remote modulation signal is faulty.
P3.4.8 reMote rate cutback SP
Menu > Optional Features > Local/Remote Mode Password Level: Technician Restricted? No
This determines the cutback setpoint for the remote ring rate. If the FlexFit is in remote mode and "P3.4.6 Remote Modulation" =
4-20 mA FR or Modbus FR and the boiler outlet temperature/pressure exceeds the "Remote Rate Cutback SP", the remote ring