RS232 (OBSOLETE):

The NV3128 Control/Command Interpreter interface is always a DCE device when operating in RS-422A mode. As shown above, the system can be configured as either DTE or DCE equipment in RS-232 mode. It should be noted, however, that the selection of DTE or DCE involves only the exchange of pins 2 and 3 at one end of the interconnecting cable. The exchange can be made in the cable, or on the controller board. The exchange may or may not need to be made depending on the pin configuration, 9 or 25, of the driving DTE. The exchange may need to be reversed if a standard 25-pin/9-pin adaptor has been added to the driving device’s serial port. Pin-out for that arrangement is shown below:

The rules of thumb presented on the following page may help you make the DTE/DCE connection.

RS-232 DCE VS. DTE DECISION (OBSOLETE)

OPTION I: If the controlling RS232 device communicates over a 25- pin serial port:

1.Configure the Control Interface Module as a DTE.

2.Use a 9-pin to 9-pin cable with no connection exchange.

3.Connect the cable to the driving, 25-pin port using a common 25- pin/9-pin adaptor such as that used to connect a mouse to a computer’s serial port. The adaptor swaps the connections.

NV3128 RS-422A Machine-Control Routing Switch

2-16

Page 40
Image 40
Envision Peripherals NV3128 manual RS232 Obsolete, RS-232 DCE VS. DTE Decision Obsolete