Programming Over RS-232-C

Extended Interface with Hardware Handshake

Extended Interface with Hardware Handshake

With the extended interface, both the software and the hardware can control the data flow between the Logic Analysis System and the controller. The Logic Analysis System uses the following connections on its RS-232-C interface for extended interface communication:

Pin 5 SGND (Signal Ground)

Pin 3 TD (Transmit Data from Logic Analysis System)

Pin 2 RD (Receive Data into Logic Analysis System)

The additional lines you use depends on your controller’s implementation of the extended hardwire interface.

Pin 7RTS (Request To Send) is an output from the Logic Analysis

 

System which can be used to control incoming data flow.

Pin 8

CTS (Clear To Send) is an input to the Logic Analysis System

 

which controls data flow from the Logic Analysis System.

Pin 6

DSR (Data Set Ready) is an input to the Logic Analysis System

 

which controls data flow from the Logic Analysis System within two bytes.

Pin 1

DCD (Data Carrier Detect) is an input to the Logic Analysis

 

System which controls data flow from the Logic Analysis System within

 

two bytes.

Pin 4

DTR (Data Terminal Ready) is an output from the Logic Analysis

 

System which is enabled as long as the Logic Analysis System is turned on.

The TD (Transmit Data) line from the Logic Analysis System must connect to the RD (Receive Data) line on the controller. Likewise, the RD line from the Logic Analysis System must connect to the TD line on the controller.

The RTS (Request To Send) is an output from the Logic Analysis System which can be used to control incoming data flow. A true on the RTS line allows the controller to send data and a false signals a request for the controller to disable data transmission.

The CTS (Clear To Send), DSR (Data Set Ready), and DCD (Data Carrier Detect) lines are inputs to the Logic Analysis System, which control data flow from the Logic Analysis System. Internal pull-up resistors in the Logic Analysis System assure the DCD and DSR lines remain high when they are not connected. If DCD or DSR are connected to the controller, the controller must keep these lines along with the CTS line high to enable the Logic Analysis System to send data to the controller. A low on any one of these

3–5