Table of Contents
Advertisement
Baud Rate (bits per second)
75
110
134.5
150
300
600
1200
DATA BITS
This control sets the data transmission to one of four formats:-
Data Bits
Description
7 + 1 parity
7 data bits + 1 parity bit
8 + 1 parity
8 data bits + 1 parity bit
8 + no parity
8 data bits + 0 parity bit
9 + no parity
9 data bits + 0 parity bit
ADDRESS
When more than one compatible instrument is connected in "daisy-chain" fashion by
coupling the AUX RS232 connector on the rear panel of the main console to the
RS232 port on the next, then this control is used to define the instrument's RS232
address. All daisy-chained instruments receive commands but only the instrument
currently being addressed will implement or respond to them, except of course the
command that changes the instrument to be addressed.
ECHO
This control, when switched on, causes the model 7124 to echo each character
received over the RS232 interface back to the controlling computer. The computer
should wait until the echoed character is returned before it sends the next character.
When switched off, character echo is suppressed.
NOTE: Character echo should always be switched on, except when controlling the
instrument manually from a simple RS232 terminal where the maximum speed
with which characters can be sent to the instrument is limited by the speed of
human typing.
PROMPT
This control has two settings, as follows:-
ON
A prompt character is generated by the model 7124 after each command
response to indicate that the instrument is ready for a new command. The prompt
character is either a "*" or a "?" If a "?" is generated, it indicates that an
overload, reference unlock, parameter error or command error has occurred.
OFF
No prompt character is generated.
DELIMITER
The character shown is that sent by the lock-in amplifier to separate two numeric
values in a two-value response, such as that generated by the MP command. The
corresponding ASCII value of this character is also shown in brackets. For example,
value 44 corresponds to a "," (comma).
Chapter 5, FRONT PANEL OPERATION
Baud Rate (bits per second)
1800
2000
2400
4800
9600
19200
38400
5-31
Advertisement
Table of Contents
