Setting Up To Use The Rs-232 Interface - Protek 9216A User Manual

Table 3-1 RS-232 Signals and Pin Assignments
Pin Signal
1 DCD
2 RX
3 TX
4 DTR
5 GND
6 DSR
7 RTS
8 CTS
9 RI
In the application of the RS232 interface to the remote control of the LCR Meter, the
meter plays the role of a modem, and the flow of data is primarily measurements trans-
mitted from the meter to the computer.

Setting Up to Use the RS-232 Interface

The 9216A is configured as a DCE (transmit on pin 3, receive on pin 2) and supports the
CTS/DTR hardware handshaking discussed above. The CTS signal (pin 8) is an output
of the meter indicating that the 9216A is ready, while the DTR signal (pin 4) is an input to
the meter that is used to control the 9216A transmissions. If desired, the handshake pins
may be ignored and a simple three-wire interface (pins 2, 3 and 5) may be used.
Before communicating with the 9216A, the RS232 characteristics must be set. As
shown in Table 3-2, the RS232 interface is configured using the rear panel switches
SW1-1 to SW1-7. The last three switches set the baud rate to 300, 600, 1200, 2400,
4800, or 9600 baud. Parity may be enabled or disabled, and set to even or odd, and, the
number of bits in a data byte may be set to 7 or 8.
Note: the 9216A must be set to eight data bits if binary data output formats are used.
Direction

Data carrier detect

Receive Data

Transmit data

Data terminal ready
—
Signal ground

Data Set Ready

Request to send

Clear to Send

Ring indicator
27
Description