3.3.3. LINE TERMINATION Rt
The application of Line Termination (terminator) Rt = 120
W
(ohms) will reduce electrical reflection in data line at high baud rate. It is
not needed below 9600Bd. The Line Termination resistor should be used if the distance is over 1000m @ 9600Bd or 700m @
19200Bd transmission, the resistor can be necessary if there are problems with the transmission correctness. The Rt terminator is
integrated in the converter and activated by the use of SW2 micro-switch.
3.4. M-1 BUS CONNECTION
Fig 8. Connection of converters by the use of M-1 bus
3.4.1. DESCRIPTION OF M-1 INTERFACE TERMINALS
Terminal
M-1 interface
TX+
Transmitting data (+)
TX-
Transmitting data (-)
GND-T
Transmitter signal ground
RX+
Receiving data (+)
RX-
Receiving data (-)
GND-R
Receiver signal ground
3.4.2. GND-R & GND-T TERMINALS CONNECTION
Connection of GND terminals of M-1 interfaces, converters connected to M-1 bus, should be done in the case of a potential difference
of the signals grounds on interfaces M-1, which prevents proper data transmission. Optionally, combine terminals GND-T withGND-R.
Cannot connect to the GND-T & GND-R terminals - cables screens, PE circuit of electrical installation, signals grounds of
other devices.
3.5. POWER SUPPLY
The power supply to ADA-M140 should be DC (regulated) from the scope 10 V= to 30V= and nominal power min. 3W eg. ZS-12/500
or DR-15-24. The power cable from DC power supplies to the device must not be longer than 3m.
Observe the polarity, connect positive (+) of DC power supplies to V+ and negative (-) end to V- terminal. ADA-M140 has the
protection from opposite connection power supply. If after power, on the front panel is not lit green LED PWR, check the power
connection (polarity).
4. CONFIGURATION
For configuration of ADA-M140 operating mode use a four-position dip switch SW1 and two-position dip switch SW2.
The locations of SW1 and SW2 are shown on the figure 1.
For setting, remove the covers and use small, flat screwdriver.
8
ADA-M140
Rt
Rt
Rx+
Rx-
GND
Tx+ / A
Tx- / B
ADA-M140
RS485/RS422
connector
M-1
connector
Rx+
GND-R
Tx+
GND-T
Vss+
Vss-
V -
V +
Power supply
Tx-
Rx-
Rt
Rx+
Rx-
GND
Tx+ / A
Tx- / B
ADA-M140
RS485/RS422
connector
M-1
connector
Rx+
GND-R
Tx+
GND-T
Vss+
Vss-
V -
V +
Power supply
Tx-
Rx-
Rt
M-1
bus
