Cables; Minimum Three-Wire Interface With Software Protocol - HP 1650B Programming Reference Manual

Cables

Minimum
Three-Wire
Interface with
Software
Protocol
Programming Over RS232C
3-2
Selecting a cable for the RS-232C interface is dependent on your specific
application. The following paragraphs describe which lines of the
HP 1650B/SlB are used to control the operation of the RS-232C relative
to the HP 1650B/51B. To locate the proper cable for your application,
refer to the reference manual for your controller. This manual should
address the exact method your controller uses to operate over the
RS-232C bus.
With a three-wire interface, the software (as compared to interface
hardware) controls the data flow between the HP 1650B/51B and the
since you can ignore hardware handshake requirements. The
HP 1650B/51B uses the following connections on its RS-232C interface for
three-wire communication:
Pin 7 SGND (Signal Ground)
l
Pin 2 TD (Transmit Data from HP 1650B/51B)
l
Pin 3 RD (Receive Data into HP 1650B/51B)
l
The TD (Transmit Data) line from the HP 1650B/51B must connect to the
RD (Receive Data) line on the controller. Likewise, the RD line from the
HP 1650BElB must connect to the TD Iine on the controller. Internal
pull-up resistors in the HP 1650B/5lB assure the DCD, DSR, and CTS
lines remain high when you are using a three-wire interface.
HP 1650B/HP 16518
Programming Reference