The Net-485 requires that some of the terminals be tied together for Half-Duplex RS485 communication. If these terminals are not wired correctly you may experience communication issues.
TXD A tied to RXD A
TXD B tied to RXD B
A = 485 + (positive)
B = 485 - (negative)
The SGND (signal ground) is not always needed, but it is required by some devices. Usually if the end device has a signal ground terminal that means it should be connected. It is also recommended to connect the Signal Ground to a stable ground reference for long distance wire runs, or if experiencing data corruption.
The RX Term and TX Term are jumper slots for the RS485 Termination. For RS485, a jumper is needed across EITHER the RX Term pins OR the TX Term pins. Having jumpers at both termination points will add too much resistance and block the data signal. Termination is not always needed for short wire lengths. If you are below 12-15 ft you can usually send data with no terminating resistor connected, although that may not be the case with every application. If the device you are connecting to or the cable you are using is already terminated, then you can remove the jumper to avoid putting too much resistance on the data lines.
The GND and 8-24VDC terminals are for the power input.
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