Stanford Research Systems SR780, Руководство по эксплуатации и программированию, Страница: 385 / 497

Remote Programming 5-19
SR780 Network Signal Analyzer
Introduction
The SR780 Network Signal Analyzer may be remotely programmed via either the RS232
or GPIB (IEEE-488) interfaces. Any computer supporting one of these interfaces may be
used to program the SR780. Both interfaces are receiving at all times, however, the
SR780 will send responses only to the Output Interface specified in the [System]
<Remote> menu.
Use the OUTX command at the beginning of every program to direct the SR780
responses to the correct interface.
Communicating With GPIB
The SR780 supports the IEEE-488.1 (1978) interface standard. It also supports the
required common commands of the IEEE-488.2 (1987) standard. Before attempting to
communicate with the SR780 over the GPIB interface, the SR780's Device Address must
be set in the [System] <Remote> menu.
Communicating With RS232
The SR780 is configured as a DCE ( transmit on pin 3, receive on pin 2) device and
supports CTS/DTR hardware handshaking. The CTS signal (pin 5) is an output indicating
that the SR780 is ready, while the DTR signal (pin 20) is an input that is used to control
the SR780's data transmission. If desired, the handshake pins may be ignored and a
simple 3 wire interface (pins 2,3 and 7) may be used. The RS232 interface Baud Rate,
Word Length, and Parity must be set in the [System] <Remote> menu.
Screen Indicators And Queues
To assist in programming, the SR780 has 4 interface indicators which are displayed at the
top of the screen.
The RS232/gpib indicator shows ‘RS232’ if the interface responses are directed to the
RS232 serial port and ‘gpib’ and the address if the interface responses are directed to the
GPIB port.
The comm indicator flashes ‘RS232’ when there is activity on the RS232 interface and
‘GPIB’ when there is activity on the GPIB interface. ‘ERR’ flashes whenever a computer
interface error occurs, such as illegal command or out of range parameter is received.
The REM indicator is on whenever the SR780 is in a remote state (front panel locked
out).
The SRQ indicator is on when the SR780 generates a service request. SRQ stays on until
a GPIB serial poll is completed.
To help find program errors, the SR780 can display the interface buffers on the screen.
This screen is accessed by <View Qs> in the [System] <Remote> menu. The last 256
characters received and transmitted by the SR780 are displayed.