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3.6 CONNECTION OF COM3 SERIAL OUTPUT
The standard instrument features a third serial output (COM3). For
information about RS232 connection, refer to § 3.5. Pin coding is the same.
3.6.1 RS422 CONNECTION
Key:
NC = Reserved - do not
connect
RX422 +/- = Received data
TX422 +/- = Transmitted data
TERMIN = Termination resistor
to be connected to pin 6
Ri = Termination resistor inside
terminal
NOTE: the free pins are
reserved for RS232 connection
Figura 3.6 –
Example of RS422 serial port connection
CAUTION
Operating limits stipulated by the standard RS422:
Maximum transmission distance = 1200 m
Maximum line voltage = +/- 7V
For connection to external devices, use a screened
twisted pair cable and connect the screen to the metal cap
of the 9-pin connector.
