DEUTSCHMANN AUTOMATION UNIGATE IC, Инструкция по эксплуатации

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5.7.13 Instruction manual UNIGATE
®
IC - Ethernet V. 2.9 41
Deutschmann Automation GmbH & Co. KG Appendix
14.2.2.4 Shield terminal lead
The shield signal for the electronic circuitry is connected to the top-hat rail via the connector pro-
vided. The shield signal for the Ethernet cable shield is not electrically connected to the shield
signal of the electronic circuitry for reasons relating to interference immunity.
14.2.3 Rotary coding switches
The rotary coding switches are socketed and can be taken off, in order to alternatively use the
pins of the shift register.
14.2.3.1 Slide switch (RS485/RS232 interface)
This slide switch is used to select whether an RS485 interface or an RS232 interface is con-
nected at the connector to the external device.
14.2.3.2 Slide switch (RS485 termination)
If the gateway is operated as the first or last physical device in the RS485 bus, there must be a
bus termination at this gateway. In order to do this, either a bus terminating resistor in the con-
nector or the resistor (150

) integrated in the gateway must be activated. In order to do this,
slide the slide switch to position ON. In all other cases, the slide switch must remain in position
OFF. Please refer to the general RS485 literature for further information on the subject of bus ter-
minations.
If the integrated resistor is used, please allow for the fact that this also activates a pull-down
resistor (390

) to ground and a pull-up resistor (390

) to VCC.
At the RS422-interface the transmission line is terminated. The receive line is always firmly
terminated.