Multi-Standard Serial Ports - Seco SBC Series User Manual

3.3.9

Multi-standard serial ports

Dual RS-232/RS-422/RS-485 pin header- CN8
Pin Signal RS-232 mode
1 COM1_RxD COM1_Rx+
2 COM2_RxD COM2_Rx+
3 COM1_TxD COM1_Tx-
4 COM2_TxD COM2_Tx-
5 GND GND
7 COM1_RTS# COM1_Tx+
8 COM2_RTS# COM2_Tx+
9 COM1_CTS# COM1_Rx-
10 COM2_CTS# COM2_Rx-
COM1_CTS#/COM2_CTS#: COM port #1 / #2x RS-232 Clear To Send handshaking signal
COM1_RX+/COM1_RX-: COM port #1 RS-422 receive differential pair
COM1_TX+/COM1_TX-: COM port #1 RS-422 Transmit differential pair
COM2_RX+/COM2_RX-: COM port #2 Full Duplex RS-485 (RS-422) Receive differential pair
COM2_TX+/COM2_TX-: COM port #2 Full Duplex RS-485 (RS-422) Transmit differential pair
COM1_Data+/COM1_Data-: COM Port #1 Half Duplex RS-485 Differential Pair
COM2_Data+/COM2_Data-: COM Port #2 Half Duplex RS-485 Differential Pair
The selection of the kind of interface (RS-232, RS-422 or RS-485) can be made via BIOS (please check par. 4.3.4.3).
Please be aware that for proper RS-485 working, the RTS# signals coming out from the N-series Intel
used as an handshaking signal, i.e. it is used to control the data flow direction. When RTS# signal is driven low, then the RS-485 port is in receiving mode, when
RTS# signal is driven high then the RS-458 port is in transmitting mode.
For Debug Purposes, COM2_TxD and COM2_RxD signals can be switched with Debug UART (PCU UART) Tx and Rx signals, respectively. This is possible,
however, only when the UART #2 is disabled. In this case, the Debug UART (which can work exclusively in RS-232 mode) can be enabled, and it will be available
SBC-A80-eNUC
SBC-A80-eNUC User Manual - Rev. First Edition: 1.0 - Last Edition: 1.2 - Author: S.B. - Reviewed by G.G Copyright © 2017 SECO S.r.l.
Signal RS-422 mode Signal RS-485 mode
COM1_Data-
COM2_Data-
GND
COM1_Data+
COM2_Data+
® ®
The N-series Intel Pentium / Celeron
embed two high speed UART controllers, which support COM ports with
flow control (RTS# and CTS# signals).
These two ports are carried, on SBC-A80-eNUC board to as many
multistandard RS-23/RS-422/RS-485
implementation of two multistandard serial ports.
These ports are available on dedicated connector CN8,
which is an internal 9-pin standard male pin header, p 2.54
mm, 5+4 pin, h= 6mm, type NELTRON p/n 2213S-10G-E06 or
equivalent.
Signals Description
COM1_RxD/COM2_RxD: COM port #1 / #2 RS-232 Receive data
COM1_TxD/COM2_TxD: COM port #1 / #2x RS-232 Transmit data
COM1_RTS#/COM2_RTS#: COM port #1 / #2 RS-232 Request to Send
handshaking signal.
® ®
Pentium / Celeron
®
and the x5-Series Atom SoCs
transceivers, allowing
®
and x5-Series Atom SoCs must be
the
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