The ability to control DCS or Maestro from a remote host is achieved through a RS-232 serial connection and the protocol described below. The serial connection is to be a 2400 baud, 8 data bit, no parity, full-duplex connection. The DCS serial connection is via the IBM AT standard 9 pin connection with the serial port configured as DTE equipment. In order to communicate with another IBM AT serial port, a modem pair may be used for long distances or for distances estimated to be up to 500 feet, a null modem wired direct connection cable may be used. The pin connections are described below:
DCS/Maestro Side |
Host Side |
|
1 Carrier Detect (Not used) |
1 Carrier Detect |
|
2 Receive Data |
<-- |
3 Transmit Data |
3 Transmit Data |
--> |
2 Receive Data |
4 Data Terminal Ready |
--> |
6 Data Set Ready |
5 Signal Ground |
---- |
5 Signal Ground |
6 Data Set Ready |
<-- |
4 Data Term Ready |
7 Request To Send (Not used) |
8 Clear To Send |
|
8 Clear To Send (Not used) |
7 Request To Send |
|
9 Ring Indicator (Not used) |
9 Ring Indicator |
The DCS or Maestro will use the Data Set Ready signal (host's Data Terminal Ready) as a 'power-on' signal from the host and likewise, DCS or Maestro will provide Data Terminal Ready to the host to indicate that it is powered-on and ready.
