Instruction manual

32 RFT9739 Field-Mount Transmitter Instruction Manual
Output Wiring
continued
Configuration for constant
current
Applications with high capacitance loading will benefit by wiring the
frequency/pulse output circuit to maintain a constant current source of
50 mA for any load between 0 and 220 ohms. This configuration renders
the control output circuit inoperable.
For constant current, add a jumper across terminals 14 and 15, and a
100 to 250 ohm resistor at the PLC or pulse-counter end of the cable, as
illustrated in
Figure 5-7
.
The control output can be reconfigured to function properly, independent
of this frequency/pulse wiring procedure. See "Control output in open
collector mode," page 36.
Figure 5-7. Frequency/pulse output wiring for constant current
CAUTION
Adding a jumper across terminals 14 and 15 renders
the control output circuit inoperable.
Do not attempt to use the control output circuit after you
add a jumper across terminals 14 and 15.
RFT9739
output terminals
PLC
or
pulse counter
RETURN (ground)
FREQ+ (signal line)
100 to 250 ohm
resistor