5 TWN4 Palon Compact
5.5 DIP Switch and Main Connector
While the module can be connected via USB port, its main host connection is either RS485 or RS232. The
RS485 / RS232 interface is accessable via X1. Table 5.2 shows the pinout of X1, figure 5.7 shows the
polarity of the pins.
Pin
Name
1
RS232_RX
(Light: N/A)
2
RS232_TX
(Light: N/A)
3
RS485_A
4
RS485_B
5
Wiegand D0 or DATA
6
Wiegand D1 or CLK
7
VIN 9-30V
8
GND
Table 5.2: X1 Pinout
For RS485, the address of each module must be adjustable. This can be done with the DIP switches. Fur-
thermore, the RS485 bias and termination can be set. Table 5.3 shows the assignment of the DIP switches.
DIP
Assignment
1
RS485 address 0 (LSB)
2
RS485 address 1
3
RS485 address 2
4
RS485 address 3 (MSB)
5
RS485 bias
6
RS485 baud rate (LSB)
7
RS485 baud rate (MSB)
8
RS485 Termination 120 Ohm
Table 5.3: DIP switches
The assignment of DIP switches relates to version with RS485. For RS232, Wiegand, Clock/Data and the
DIP switches are not in use.
The behaviour of the DIP switches 1-7 is controlled by firmware and may change in future.
When switch 5 / RS485 bias is switched on, a pull-up resistor is connected to RS485_A and a pull-down
resistor is connected to RS48_B signal. This prevents an undefined state of the bus when no transmitter
is active.
Switch 8 / RS485 Termination 120 Ohm connects a 120 Ohm resistor between RS485_A and RS485_B
signal, which prevents reflections on the bus.
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