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MDS Orbit MCR-4G Technical Manual
MDS 05-6628A01, Rev. B
COM Port
—This
connector serves as the serial interface port for both console management and payload
data. It allows for connection of data equipment in the common Serial signaling standard. By default, the
port is enabled for local console control. The COM port serves as the primary interface for connecting the
unit to an external DTE serial device supporting the RS-232 or RS-485 serial data format. If necessary, an
adapter may be used to convert the unit’s RJ-45 serial jack to a DB-9F type (GE MDS part no. 73-2434A12).
NOTE:
Not all PCs include a serial port. If one is not available, the unit’s USB port may be used to access
the device management interface. Alternatively, a PC’s USB port may be used with a
USB-to-Serial adapter and appropriate driver software. These devices are available from several
manufacturers.
The COM port supports a serial data rate of 1200-115200 bps (115200 default, asynchronous only). The unit
is hardwired as a DCE device. Supported data formats for the COM port are:
8N1
- 8 char bits, no parity, 1 stop bit
(Default setting)
8N2
- 8 char bits, no parity, 2 stop bits
8O1
- 8 char bits, odd parity, 1 stop bit
8O2
- 8 char bits, odd parity, 2 stop bits
8E1
- 8 char bits, even parity, 1 stop bit
8E2
- 8 char bits, even parity, 2 stop bits
7N1
- 7 char bits, no parity, 1 stop bit
7N2
- 7 char bits, no parity, 2 stop bits
7O1
- 7 char bits, odd parity, 1 stop bit
7O2
- 7 char bits, odd parity, 2 stop bits
7E1
- 7 char bits, even parity, 1 stop bit
7E2
- 7 char bits, even parity, 2 stop bits.
The tables below provide pin descriptions for the COM1 data port in RS-232 mode and RS-485 modes,
respectively.
NOTE:
The COM2 port, if present, is restricted to RS-232 mode; it cannot be used for RS-485.
(As viewed from the outside of the unit)
Table 2. COM1/2 Port Pin Details (RS-232)
Pin
Number
Input/Output
Pin Description
1
Reserved
2
OUT
DCD (Data Carrier Detect)
3
Reserved
4
Ground
Connects to ground (negative supply potential) on chassis
5
OUT
RXD (Received Data)—Supplies received data to the connected device
6
IN
TXD (Transmitted Data)—Accepts TX data from the connected device
7
OUT
CTS (Clear to Send)
8
IN
RTS (Ready to Send)
