Toradex Apalis Series - Reference Schematics

Apalis Carrier Board Design Guide
Toradex AG l Altsagenstrasse 5 l 6048 Horw l Switzerland l +41 41 500 48 00 l www.toradex.com l info@toradex.com
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2.15.2 Reference Schematics
2.15.2.1 Full-Featured RS232 Reference Schematics
The RS232 interface can be classified as Data Terminal Equipment (DTE) or Data Communication
Equipment (DCE). This classification is inherited from the usage of the interface for modems. The
signal direction of these modes is different. Some Apalis modules might allow changing the mode
and therefore also the data direction, but this is not a mandatory requirement. According to the
Apalis specifications, the interface is intent to be used in the DTE configuration.
Signal
Name
Usage
DTE Direction
(Apalis standard)
DCE Direction
UART1_RXD
Received Data
Data from DCE to DTE
Input
Output
UART1_TXD
Transmitted Data
Data from DTE to DCE
Output
Input
UART1_RTS
Request to Send
DTE request to DCE to be prepared to
receive data
Output
Input
UART1_CTS
Clear to Send
DCE indicates ready to accept data
Input
Output
UART1_DTR
Data Terminal Ready
DTE indicates presence to DCE
Output
Input
UART1_DSR
Data Set Ready
DCE is ready to receive commands or data
Input
Output
UART1_RI
Ring Indicator
DCE announce to have detected an incoming
ring signal on the telephone line
Input
Output
UART1_DCD
Data Carrier Detect
DCE announce to be connected to the
telephone line
Input
Output
Table 26: RS232 Signal Modes
Figure 45: RS232 Reference Schematic
2.15.2.2 RS422 Reference Schematics
The RS422 is a full-duplex serial interface with differential pair signals. This allows higher data
rates over longer distances as with the RS232. Since the RS422 has separate RX and TX signal
pairs, no additional control signals are required for changing the signal direction. This means, the
RS422 requires only the RX and TX signals of the UART interface. Therefore, it is possible to use any
of the four standard UART interfaces of the Apalis standard.
The RS422 specification does not contain a connector. Therefore, there is no standard connector
for this interface available. The reference schematic below uses the 9-pin D-sub connector (DE-9).
Peripherals might have a different pin-out even if they use as well a DE-9 connector.
MM70-314-310B1
UART1_RXD
118
Apalis - UART
10 of 25
UART1_TXD
112
UART1_CTS
116
UART1_RTS
114
UART1_DCD
124
UART1_DSR
120
UART1_DTR
110
UART1_RI
122
UART2_RXD
132
UART2_TXD
126
UART2_CTS
130
UART2_RTS
128
UART3_RXD
136
UART3_TXD
134
UART4_RXD
140
UART4_TXD
138
X1J
MXM3_118_M
MXM3_112_M
MXM3_114_M
MXM3_116_M
MXM3_124_M
MXM3_120_M
MXM3_110_M
MXM3_122_M
22RRA8B
22RRA8C
22RRA8D
22RRA10A
22RRA10B
22RRA10C
22RRA10D
22RRA8A
SN65C3243DBR
T3IN
12
T2IN
13
T1IN
14
R2OUTB
20
R1OUT
19
R2OUT
18
R3OUT
17
R4OUT
16
R5OUT
15
FORCEOFF#
22
FORCEON
23
INVALID#
21
T1OUT
9
T2OUT
10
T3OUT
11
R1IN
4
R2IN
5
R3IN
6
R4IN
7
R5IN
8
IC7A
178-009-613R571
L1
L2
L3
L4
L5
L6
L7
L8
L9
X28B
GND
UART1_RS232_L_RTS
UART1_RS232_L_TXD
UART1_RS232_L_DTR
UART1_RS232_L_DCD
UART1_RS232_L_RI
UART1_RS232_L_DSR
UART1_RS232_L_RXD
UART1_RS232_L_CTS
UART1_RS232_L_RTS
UART1_RS232_L_TXD
UART1_RS232_L_DTR
UART1_RS232_L_DCD
UART1_RS232_L_RI
UART1_RS232_L_DSR
UART1_RS232_L_RXD
UART1_RS232_L_CTS
UART1_CTS
UART1_DSR
UART1_RI
UART1_DCD
UART1_DTR
UART1_TXD
UART1_RTS
3.3V_SW
3.3V_SW
UART1_RXD
SN65C3243DBR
VCC
26
V+
27
C1+
28
C1-
24
GND
25
V-
3
C2+
1
C2-
2
IC7B
GND
GND
100nF
16VC48
100nF
16V
C44
100nF
16V
C51
100nF
16V
C45
100nF
16V
C49
3.3V_SW
UART1_CTS
UART1_DSR
UART1_RI
UART1_DCD
UART1_DTR
UART1_TXD
UART1_RTS
UART1_RXD