Macurco DVP-120 User Instructions page 9

Each 8-terminal sensor modular connector may be disconnected from the PCB connector to ease wire installation. The terminals will
accept wire from 16 to 28 AWG. To install a wire, strip back approximately 0.25 in. (6 mm) of insulation, and insert the bare wire into
the terminal. Tighten the screw clamp and ensure that the wire cannot be easily pulled from the connector. Connector to sensor C1
through C12 correspondence to all 12 input channels.
DVP-120M
A MODBUS over Serial Line Cable should be shielded for best performance. The shield should be connected on each detector at SHD
terminal and connected to a ground terminal or chassis only at one end of the bus. An RS485-MODBUS must use a balanced pair (for
A-B) and a third wire (for the Common). For RS485-MODBUS, Wire Gauge must be chosen sufficiently wide to permit the maximum
length (1000 m or 3281ft). AWG 24 is always sufficient for the MODBUS Data. Category 5 cables may operate for RS485-MODBUS, to
a maximum length of 600 m 1968.5 ft. For the balanced pairs used in an RS485-system, wire with a characteristic impedance of higher
than 100 Ohms may be preferred, especially for 19200 and higher baud rates.
Note: It is recommended to always use twisted wires to reduce noise and allow for reliable data communication over greater distances.
Use at least 3-conductor wire with one twisted pair providing a pair for signal (A & B) and common (COM) connections.
For best performance use shielded 3-conductor wire with one twisted pair providing a pair for signal (A & B), common (COM) and
shield ground (SHD) connections.
Figure 2-5 Sensor Interface Connector – Channels 5 and 6
Wire gauge Maximum Run Length (ft.)
18
16
14
Table 2-2 Recommended Wire Gauge
(feet) (meters)
500 152
800 244
1250 381
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