Installation
Page 7
May 2020
DSY-PM-01378-EN-08
INSTALLATION
Connecting the B2900 Monitor to a Frequency Output Device
The B2900 monitor has two jumpers for setting the type of signal and the minimum
amplitude of the signal that it accepts� First, establish the type of output provided by the
flow sensor� The outputs almost always fall into one of two types�
• Type 1 is the unaltered frequency signal coming from an un-amplified
magnetic pickup� This signal is normally a sine wave in appearance, and
the amplitude of the waveform varies with the flow� Small turbines have
comparatively small rotating masses so they produce a smaller amplitude
waveform and higher frequencies than larger turbine sensors�
• Type 2 is the frequency signal from the transducer amplified, wave shaped or
both to produce a waveform of a specified type and amplitude� Most amplified
transducers output a square wave shape at one of many standard amplitudes�
For example, a popular amplified output is a 10V DC square wave�
If the flow sensors output signal is type 1, you must also determine the minimum
amplitude of the frequency output� The B2900 monitor has a high or low signal sensitivity
setting� Use the high signal sensitivity (30 mV) with low amplitude (usually small) turbine
flow sensors� Use the low signal sensitivity setting (60 mV) for larger turbines and amplified
transducers� See
Use the high signal sensitivity setting where the minimum signal amplitude is below 60 mV�
Setting the sensitivity higher than necessary may allow noise interference�
JP1
JP2
JP3
Input
Total P
ulse
Sig
nal
TB1
Mag
Pulse
Iso
OC
Low
High
Input Waveform Selection
(Magnetic Pickup Selection Shown)
Input Signal Level Selection
(Low Signal Sensitivity (60 mV) Selection Shown)
Figure 2: Input jumper settings (NEMA 4X)
When the type of waveform and input signal level (amplitude) are determined, set the
jumpers on the B2900 monitor circuit board�
For typical variable reluctance magnetic pickups, set the waveform selection jumper
for Mag� Determine the setting for the input level by looking at the magnetic pickup
specifications� If the minimum amplitude at the minimum rated flow is greater than 60 mV,
use the low signal sensitivity jumper position� See
