Relay 2
(TB3)
Relay 1
(TB2)
50-604 Kotron Model 804 Sentinel II RF Level Transmitter
10
2.4.2 Wiring Operation
2.4.2.1 4–20 mA output wiring
Connect the positive wire to the
+ terminal; connect the negative wire
to the – terminal.
2.4.2.2 Active or passive selection
The 4–20 mA output can be config-
ured for active or passive operation.
Active mode allows the Sentinel II
to drive the loop (for example, the
Sentinel II is the 24 VDC power
supply). The passive mode allows the
Sentinel II to react like a loop-powered
transmitter (the loop power is supplied
elsewhere). Switch S1 changes the
mode. See Figure 6 on page 9
.
Cable should be shielded, twisted pair,
22 gauge stranded conductors. In the
active mode of operation the shield
should be grounded at the model 804.
In the passive mode the shield should
be grounded at the power source.
Caution:
Applying power to the 4–20 mA output, while in the active
mode, will seriously damage the instrument.
2.4.2.3 RS-485 output
RS-485 communication is achieved by means of a 2-wire,
twisted pair connected to terminal block.
1. Connect the A wire from the control room converter to
terminal A.
2. Connect the control room converter wire B to terminal B.
NOTE: Polarity among units in loop must be observed.
3. If connecting multiple 804 units in a daisy chain configu-
ration, be sure to connect the wiring in parallel and have
the ending 804 unit with the termination resistor
jumpered. The termination jumper pins are located under
the shield, below the RS-485 terminal block. The jumper
(JP1) should be in positions 2 and 3, removed on all units
except the last one in the chain. The last unit should have
the jumper in positions 1 and 2.
4. Proceed to
Unit Configuration
section on page 11.
NOTE: If connecting several units, note the color wire used for A and
B; ensure that the same designated color is used for each
of the units.
NO
CO
NC
NO
CO
NC
NO
CO
NC
NO
CO
NC
Relay 4
(TB4)
Relay 3
(TB5)
L1 (+)
Not used
L2/N (–)
Input
power
(TB1)
Figure 7
Power Supply Board
Terminal Connections
