Modem Control Signals - PictureTel Concorde 4500 Servicing Manual

Modem Control
Signals
The Concorde¥4500 and the control port devices use modem control
signals to communicate with each other when they want to send or
receive information. This is referred to as handshaking.
For example, when a device wants to send data to data port B on the
Concorde¥4500, the following scenario takes place:
1. The device asserts the RTS signal on pin 4.
2. The Concorde•4500 responds that it is ready to receive the data by
raising the CTS signal on pin 5.
3. When the device senses that the CTS signal is asserted, it sends the
data on pin 2, TD.
This example is simpliÞed for illustrative purposes. Usually,
additional handshaking takes place before and after data is
exchanged.

Modem Control Signals

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