Crestron MC2E 2-Series Professional Media Controller
NOTE: To support RS-485, tie pin 1 (RXD-) to pin 9 (TXD-) and pin 4 (TXD+) to
pin 6 (RXD+) in the cable. Refer to the table after this note, titled "COM Pinout to
RS-485 Bus".
Non-Standard COM Pinouts
PIN DIRECTION DESCRIPTION
1* To MC2E (RXD-) RS-422 Receive Data (Idles Low)
2 To MC2E (RXD) RS-232 Received Data
3 From MC2E (TXD) RS-232 Transmitted Data
4 From MC2E (TXD+) RS-422 Transmit Data (Idles High)
5 Common RS-232 and RS-422 Signal Common
6 To MC2E (RXD+) RS-422 Receive Data (Idles High)
7 From MC2E (RTS) RS-232 Request To Send
8 To MC2E (CTS) RS-232 Clear To Send
9 From MC2E (TXD-) RS-422 Transmit Data (Idles Low)
Where *= RS-422 transmit and receive are balanced signals requiring two lines plus a ground in
each direction. RXD+ and TXD+ should idle High (going Low at the start of data transmission).
RXD- and TXD- should idle Low (Going High at the start of data transmission). If necessary,
RXD+/RXD- and TXD+/TXD- may be swapped to maintain correct signal values.
COM Pinout to RS-485 Bus
COM (DB9)
CONNECTOR
RS-485 BUS
Tie Pins 1 & 9 -
Tie Pins 4 & 6 +
Pin 5 G
For more information, refer to “Slot 6: C2I-MC2-COM2” on page 30.
COMPUTER COMPUTER
This DB9F connector is used when programming the unit with a PC. The port is
modem compatible. The modem and/or PC program cable are not included. Supports
baud rate of up to 115 Kb. Use with a standard DB9 straight through cable.
Standard DB9 Pin Assignments
PIN # ABBREVIATION DESCRIPTION
1 DCD Data Carrier Detect
2 RD Receive Data
3 TD Transmit Data
4 DTR Data Terminal R eady
5 SG Signal Ground
6 DSR Data Set Ready
7 RTS Request To Send
8 CTS Clear To Send
9 Ring Ring Indicator
5 4 3 2 1
9 8 7 6
Female DB9 Connector
6 7 8 9
1 2 3 4 5
Male DB9 Connector
NOTE: DTR, pin 4 and DSR, pin 6 are not normally used.
Operations Guide – DOC. 6142 2-Series Professional Media Controller: MC2E • 7