Data-Link Terminator - ABB AW400 Series Instruction Manual

10.4 Data-link Terminator

The datalink impedance should be 110 Ohm.
When the serial communication standard is selected as RS422 or RS485, and more than one AW400 are
installed on the same datalink, it is necessary to activate a terminator resistance, which is available on the
serial communication board.
This operation is to be made only on the last AW400 connected on the serial link.
If the host computer serial port is already equipped with a 220 Ohm resistor, then an identical resistor is to be
activated in parallel to obtain a 110 Ohm loop impedance. If no such resistor is present on the Host side, then
a 110 Ohm resistor is selected on the AW400 serial board.
The terminator resistance selection is made by installing a jumper on JP1 or JP2 for RS422 or RS485
respectively: the 110 Ohm resistor is selected by jumper between pin 1-2, while the 220 Ohm resistor is
selected by jumper between pin 2-3.
jumpers
Please note:
- to select RS232 weld jumpers onto position 1,2 and 3.
- to select RS485 weld jumpers onto position 6 and 8.
- to select RS422 weld jumpers onto position 4,5,6,7 and 8.
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