Serial Port 2 Connector In Rs-485 Mode (Cn6, Pin 11-20) - Avalue Technology AMD Geode E2047551001R User Manual

ECM-5510
2.4.18 Serial Port 2 Connector in RS-485 Mode (CN6,
2.4.18.1 Signal Description – Serial Port 2 Connector in RS-485 Mode (CN6,
11-20)
Signal
DATA+/-
Do not select a mode different from the one used by the connected peripheral,
as this may damage CPU board and/or peripheral.
The transmitter drivers in the port are short circuit protected by a thermal
protection circuit. The circuit disables the drivers when the die temperature
reaches 150 °C.
RS-422 mode is typically used in point to point communication. Data and
control signal pairs should be terminated in the receiver end with a resistor
matching the cable impedance (typical 100-120 Ω). The resistors could be
placed in the connector housing.
RS-485 mode is typically used in multi drop applications, where more than 2
units are communicating. The data and control signal pairs should be
terminated in each end of the communication line with a resistor matching the
cable impedance (typical 100-120 Ω). Stubs to substations should be
avoided.
42 ECM-5510 User's Manual
This differential signal pair sends and receives serial data to the communication
link. The mode of this differential signal pair is controlled through the RTS
register of Serial Port 2. Set the RTS register of the Serial Port 2 to LOW for
transmitting, HIGH for receiving.
Pin 11-20)
Signal PIN
DATA+ 11
DATA- 13
GND 15
NC 17
NC 19
Signal Description
PIN Signal
12 NC
14 NC
16 NC
18 NC
20 NC
Pin