Switches; Termination Rx 422 + Tx 422 (Serial Interface); Rotary Coding Switches S4 + S5 (Serial Interface) - Softing echolink one2PROFINET Instruction Manual

Hardware ports, switches and LEDs
9.4

Switches

The Gateway features 4 switches with the following functions:
Termination Rx 422
Termination Tx 422
Rotary coding switch S4
Rotary coding switch S5
9.4.1

Termination Rx 422 + Tx 422 (serial interface)

If the Gateway is operated as the physically first or last device in an RS485-bus or as 422, there
must be a bus termination at this Gateway. In order to do this the termination switch is set to posi-
tion ON. The resistor (150) integrated in the Gateway is activated. In all other cases, the switch
remains in position OFF.
Please refer to the general RS485 literature for further information on the subject of bus termina-
tions.
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 RS48 only the Tx 422-switch must be set to ON.
The Rx 422-switch has to be on OFF.
9.4.2

Rotary coding switches S4 + S5 (serial interface)

Via these two switches the RS485 -ID of the gateway is set to hexadecimal, as long as an ID is
necessary for the bus. (A conversion table from decimal to hexadecimal can be found in the
appendix.) This value is read in when the Gateway is switched on. The switch positions "EE"
(testmode) and "FF" (config mode) are not possible for RS422- or RS485-operation.
Note: The switch position "DD" (ie, S4 and S5 in position "D") is reserved for internal purposes.
45
switchable Rx 422-terminating resistor for the serial interface
switchable Tx 422- or RS485-terminating resistor for the serial
interface
ID High for serial interface i. e. configmode
ID Low for serial interface i. e. configmode
echolink one2PROFINET V. 1.0
Softing Industrial Automation GmbH
15.1.15