Table 3-14. Rear Connector Naming Scheme; Table 3-15. Remote-Mount Interconnect Board Connector Naming Scheme - Motorola ASTRO Digital XTL 5000 Detailed Service Manual

3-70
This radio meets EIA compatibility with external data accessory devices. The naming scheme (see
Table 3-14 and
RS-232 naming schemes. This is due to the microcontroller's pin names versus I/O direction,
compared to the EIA pin names versus I/O direction. Therefore, a matching naming scheme has
been developed. If the pin is coming from the UART, the pin name has UART in the name. However,
if you want to know how the EIA standard identifies the pin, a chart exists that provides the naming
conversion. The shipping rear data cable automatically routes the pins according to the EIA
standard, so interfacing to external data devices, such as computers, is done correctly. The naming
scheme information is only needed when the rear connector is opened and the wires need to be
identified for connection to a custom device. Note that the correct interfacing of RS-232 lines is
"output line" to "input line". For example, the TX pin of one device connects to the RX pin of the other
device, and the RTS pin of one device connects to the CTS pin of the other device. Never connect
TX to TX, RX to RX, and so on.
J2
Radio Pin
Pin J2 Pin Name
Direction
No.
Output 4 UARTA_TX
Input 5 UARTA_RX
Output 10 UARTA_CTS
Input 11 UARTA_RTS

Table 3-15. Remote-Mount Interconnect Board Connector Naming Scheme

Radio
J6
Pin
Pin J2 Pin Name
Direc-
No.
tion
Output 2 RS232_RXD
Input 3 RS232_TXD
Output 17 RS232_CTS
Input 4 RS232_RTS
May 25, 2005
Table 3-15) used for the microcontroller's RS-232 lines sometimes conflict with EIA

Table 3-14. Rear Connector Naming Scheme

EIA-
Compatible
Pin Alternate
Name at
Name
Rear Conn.
No Change TX_DCE
No Change RX_DCE
Becomes RTS RTS_DCE
Becomes CTS CTS_DCE
EIA-
Pin Compatible
Alternate Name at
Name Rear Conn.
J2
Becomes TX_DCE
TX
Becomes RX_DCE
RX
Becomes RTS_DCE pin 17 = RTS_DCE
RTS
Becomes CTS_DCE
CTS
Theory of Operation: Controller Section
P2 Rear
Accessory Cable
DB9 (Female) =
DCE Interface
J2
TX_DCE = pin 2
RX_DCE = pin 3
RTS_DCE = pin 8
CTS_DCE = pin 7
Note: Connecting to a computer = DTE device
P2 Rear HKN6122 Data
Accessory Cable Cable DB9
DB9 (Female) = (Female) = DCE
DCE Interface Interface
pin 2 = TX_DCE TX_DCE = pin 2
pin 3 = RX_DCE RX_DCE = pin 3
RTS_DCE = pin 8
pin 4 = CTS_DCE CTS_DCE = pin 7
Note: Connecting to a computer = DTE device
DB9 (Male) Serial
Port Connector =
DTE Interface
<-->
pin 2 = RX_DTE
<-->
pin 3 = TX_DTE
<-->
pin 8 = CTS_DTE
<-->
pin 7 = RTS_DTE
TX to RX and RTS to CTS
DB9 (Male)
Serial Port
Connector =
DTE Interface
<--> pin 2 = RX_DTE
<-->
pin 3 = TX_DTE
<-->
pin 8 = CTS_DTE
<-->
pin 7 = RTS_DTE
TX to RX and RTS to CTS
6881096C74-B
Data
Device Pin
Direction
Input
Output
Input
Output
Data
Device
Pin
Direc-
tion
Input
Output
Input
Output