KBox A-103 – User Guide, Rev. 3.0
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5.1.2.
Serial Port COM2 (X204) Configuration for RS422 or RS485 via DIP Switches
The serial port COM 2 is connected to J42 on the motherboard. It can be configured for RS232 (without any
configuration) or for RS422 or RS485 serial communication (with an external module at the rear side of the COM
connector) via an on-board DIP switch (SW1). For pin assignment refer to subsection 11.1.7 to 11.1.10.
In order to change the factory configuration of the RS422/RS485 port [factory settings: refer to the grey highlighted
settings of the SW1 (DIP1-DIP8) (Figure 27, Table 1, Table 2 and Table 3)] proceed as follows:
The new port configuration has to be set before the system is installed onto a table, wall or
into an industrial cabinet. The system must be disconnected from the power source.
Disconnect all peripherals. Before you begin, ensure that you have a clean, flat and ESD-safe
surface to work on.
1.
Open the KBox A-103 as described in the section 5.1 “Opening and Closing the KBox A-103”, steps 1 to 4.
2.
Locate the DIP switches in the unit (refer to Figure 23, pos. 15 and Figure 26).
3.
By use of an insulated thin tool (e. g. screwdriver or a stylus) set the DIP switches to the up (for ON) or down (for
OFF) position corresponding the needed port configuration; refer to (Figure 27, Table 1, Table 2 and Table 3).
Figure 26: DIP1-DIP8 switches (shown with factory settings)
The optional settings (SW1) for RS485 mode communication allow the system’s operation either in full duplex mode
or in half duplex mode (see tables on the next page). While running in RS485 half-duplex mode the system stays
permanently in a receiver mode. The switch to transmission mode will be done automatically. The user can determine
if the automatic mode switch to transmission mode should be triggered by the RTS-line or should be triggered by the
last sent message using the TxD line.
If triggered by RTS has been selected, then the RTS-signal must be activated by the application software before
transmission of the data packets starts; and RTS signal has to be disabled again after termination of data
transmission.
If TxD line will be used for the mode transceiver switch process, the receiver device has to follow a timeout before
starting to send any data.
Figure 27: DIP-Switch (SW1) with DP1 to DP8 for RS422/RS485 serial communication settings (for COM 2)
DIP Switches (DIP1-DIP3)
in OFF position (factory
settings)
DIP Switches (DIP4-DIP8)
in ON position (factory
settings)