5
Figure 9: Sample Wiring diagram to Modbus Network
Note 1: Biasing, circuitry, and resistors for PU, PD, and NT terminals are integral part of 340MB transmitter .
Note 2: For the final 340MB transmitter in a given Modbus network, NT, PU, and PD jumpers should be in “open” position . Otherwise,
NT, PU, and PD should be in the “closed” position .
Note 3: For the final 340MB transmitter in a given Modbus network, all three network terminals (+), (-), and REF should be connected
to the Modbus buss . Otherwise, connect only terminals (+), (-) to the Modbus buss .
Temperature Element Wiring
Thermistors
Badger Meter thermistors are not polarity sensitive . The thermistor
located closest to the flow sensor, termed temperature sensor T1,
should be connected to terminals 2 and 3 on terminal block Temp 1 .
The thermistor located farthest from the flow sensor, termed tem-
perature sensor T2, should be connected to terminals 2 and 3 on
terminal block Temp 2 . As shown in the thermistor wiring diagram,
it is strongly recommended to install a jumper between terminals
1 and 3 for both thermistors . This is considered good practice for
all unused inputs to limit electromagnetic interference .
resistance Temperature detectors (rTd’s)
Badger Meter RTD’s are three-wire devices . Two of these wires
are the same color, and one of these two wires is used for lead
compensation . The lead compensation wire is attached to ter-
minal 1 . The other common color lead is attached to terminal 3 .
The single color lead is attached to terminal 2 . The RTD located
closest to the flow sensor, termed temperature sensor T1, should
be connected to terminal block Temp 1 . The RTD located farthest
from the flow sensor, termed temperature sensor T2, should be
connected to terminal block Temp 2 .
Connecting the Modbus Buss
As shown in the Modbus Sample Wiring Diagram, the position
of jumpers on each 340MB transmitter and wiring between each
340MB transmitter and the Modbus network are different depend-
ing on where the transmitter is installed, i .e . its nodal position .
For all but the final 340MB transmitter in a Modbus network, the
three jumpers NT, PU, and PD should be in the open position,
and only the (+) and (-) network terminals should be connected
to the Modbus buss . For the final 340MB transmitter in a Modbus
network, the three jumpers NT, PU, and PD should be in the closed
position, and all three network terminals (+), (-), and REF should
be connected to the Modbus buss .
Note: The Model 340MB transmitter default polling address
must be changed before it is introduced into an existing
network to avoid possible address conflicts. Please refer to
programming instructions in the next section.
Figure 8: rTd Wiring diagram
+5 VDC
Ω
Ω
Ω
Ω
Ω
Ω
1
2
3
Temp 1
1
3
Temp 2
2
Node "n"
Supply
Retur
n
Supply
Retur
n
Temp 2
1
2
3
Temp 1
1
3
2
Node 1
Comm LED
REF
PU
PD
NT
_
+
47k
120
47k
Comm LED
REF
PU
PD
NT
_
+
+5 VDC
47k
120
47k
REF
-
+
Modbus
PU
Note 2
Note 1
Note 2
Ω
10k
Thermistors
Jumpers
Note 3
100
Ω
RTD’s or 1000
Ω
RTD’s
NT
PD
PU
NT
PD
RTU/ASCII
T2
T1
T2
T1
+5 VDC
Ω
Ω
Ω
Ω
Ω
Ω
1
2
3
Temp 1
1
3
Temp 2
2
Node "n"
Supply
Retur
n
Supply
Retur
n
Temp 2
1
2
3
Temp 1
1
3
2
Node 1
Comm LED
REF
PU
PD
NT
_
+
47k
120
47k
Comm LED
REF
PU
PD
NT
_
+
+5 VDC
47k
120
47k
REF
-
+
Modbus
PU
Note 2
Note 1
Note 2
Ω
10k
Thermistors
Jumpers
Note 3
100
Ω
RTD’s or 1000
Ω
RTD’s
NT
PD
PU
NT
PD
RTU/ASCII
T2
T1
T2
T1
+5 VDC
Ω
Ω
Ω
Ω
Ω
Ω
1
2
3
Temp 1
1
3
Temp 2
2
Node "n"
Supply
Retur
n
Supply
Retur
n
Temp 2
1
2
3
Temp 1
1
3
2
Node 1
Comm LED
REF
PU
PD
NT
_
+
47k
120
47k
Comm LED
REF
PU
PD
NT
_
+
+5 VDC
47k
120
47k
REF
-
+
Modbus
PU
Note 2
Note 1
Note 2
Ω
10k
Thermistors
Jumpers
Note 3
100
Ω
RTD’s or 1000
Ω
RTD’s
NT
PD
PU
NT
PD
RTU/ASCII
T2
T1
T2
T1
Figure 7: Thermistor Wiring diagram
PRELIMINARY
