Ametek 7280 Instruction Manual page 166

Chapter 6, COMPUTER OPERATION
GP [n
RSADD [n]
\N n
DD [n]
ST
6-32
[n ]] Set/Read GPIB parameters
1 2
n sets the GPIB address in the range 0 to 31
1
n sets the GPIB terminator and the test echo function according to the following
2
table:
n Terminator
0 [CR], test echo disabled
1 [CR], test echo enabled
2 [CR,LF], test echo disabled
3 [CR,LF], test echo enabled
4 no terminator, test echo disabled
5 no terminator, test echo enabled
In all cases the EOI line is asserted with the last byte of a response.
When the test echo is on, every character transmitted or received via the GPIB port is
echoed to the RS232 port. This is provided solely as an aid to program development
and should not be enabled during normal operation of the instrument.
Set/read RS232 address
The value of n sets the RS232 address in the range 0 to 15. This is relevant only
when using more than one instrument connected via the RS232 "daisy-chain"
method. Each instrument must be set to a unique address.
Address command
When the model 7280 is daisy-chained with other compatible instruments this
command will change which instrument is addressed. All daisy-chained instruments
receive commands but only the currently addressed instrument will implement or
respond to the commands. The exception is the \N n command. If n matches the
address set from the front panel or via the RSADD command the instrument will
switch into addressed mode. If n does not match the address set from the front panel
the instrument will switch into unaddressed mode. Note that the \N n command does
not change the address of an instrument but which instrument is addressed.
NOTE: All instruments must have a unique address.
Define delimiter control
The value of n, which can be set to 13 or from 32 to 125, determines the ASCII value
of the character sent by the lock-in amplifier to separate two numeric values in a two-
value response, such as that generated by the MP (magnitude and phase) command.
Report status byte
Causes the lock-in amplifier to respond with the status byte, an integer between 0 and
255, which is the decimal equivalent of a binary number with the following bit-
significance:
Bit 0 Command complete
Bit 1 Invalid command
Bit 2 Command parameter error
Bit 3 Reference unlock
Bit 4 Overload