FL4000
36
3.6.11 MODBUS (RS-485) Output
Table 19: MODBUS Terminals
Terminal Block
Connection Point
Setting
P1
Term 5
COM1+ (A)
P1
Term 6
COM1- (B)
P2
Term 2
COM2- (B)
P2
Term 3
COM2+ (A)
The connections for the MODBUS output are shown in Table 19. The MODBUS connection is
used to either query the unit’s status or to configure the unit. See Section 4.0 for detailed
information on MODBUS protocol.
3.6.12 Chassis Ground
Table 20: Chassis Ground Terminal
Terminal Block
Connection Point
Block Name
Setting
P1
Term 10
CHGND
Chassis Ground
For proper operation of the detector, the FL4000 must be grounded through a wire to the
chassis. Table 20 shows the terminal block and connection point for the chassis ground
terminal. Failure to establish a ground connection can lead to greater susceptibility of the
detector to electric surges, electromagnetic interference, and ultimately, damage to the
instrument.
3.7 Switch Selectable Options
All settings on the FL4000 are selected via a dipswitch on the Power/Relay board or via
MODBUS (overrides switch settings). To set these options, remove the detector head from the
Base Assembly and locate the dipswitch (Figure 23). On the dipswitch, ON/CLOSED means
the switch is pushed in on the side labeled ON or CLOSED (opposite the OPEN side).
OFF/OPEN means the switch is pushed in on the side with the number corresponding to the
switch position or the side labeled OPEN – refer to Table 21 for dipswitch assignments. The
settings for the WARN and ALARM outputs are covered in Section 3.6
3.7.1 Time Delay Settings
Time delay set via dip switch guarantees that FL4000 will not go into ALARM mode (20 mA) if
the flame source is removed within 50% of set delay time from the start of flame. The unit will
always go into WARN mode (16 mA) upon seeing a flame source.