MGate MB3660 Modbus Gateway
Getting Started
2-2
Connecting the Power
The unit can be powered by connecting a power source to the terminal block for DC models or power connector
for AC models.
For DC power input models:
1.
Loosen or remove the screws on the terminal block.
2.
Connect the 20-60 VDC power line to the terminal block.
3.
Tighten the connections using the screws on the terminal block.
For AC power input models:
•
Connect the 100-240 VAC power line to the AC connector.
Note that the unit does not have an on/off switch. It automatically turns on when it receives power. The PWR
LED on the front panel will glow to indicate that the unit is receiving power. There are two DC power inputs for
redundancy.
Connecting Serial Devices
The unit’s serial port(s) are located on the back panel. If you are connecting an RS-485 multidrop network with
multiple devices, note the following:
•
All devices that are connected to a single serial port must use the same protocol (i.e., either Modbus RTU
or Modbus ASCII).
•
Each master device must connect to its own port on the unit. If you are connecting to a network with both
master and slave devices, the master must be connected to a separate port from the slaves.
For serial port pin assignments, refer to the
Pin Assignments
section.
RS-485 Termination and Pull High/Low Resistors
In some critical RS-485 environments, you may need to add termination resistors to prevent the reflection of
serial signals. When using termination resistors, it is important to set the pull high/low resistors correctly so
that the electrical signal is not corrupted. For each serial port, DIP switches or jumper settings are used to set
the pull high/low resistor values. A built-
in 120 Ω termination resistor can also be enabled.
To modify the termination and pull high/low resistor settings, refer to the hardware reference chapter for your
model.
ATTENTION
Do not use the 1 KΩ pull high/low setting on the MGate
MB3660 when using the RS-232 interface. Doing so will
degrade the RS-232 signals and reduce the effective communication distance.
