Computer Interfaces (Rs232 And Gpib) - Ametek 7280 Instruction Manual

Magnitude outputs would be stored. The permitted values of n would therefore be 0
and 2, so that DCB 0 would transfer the X channel output curve and DCB 2 the
Magnitude curve.
Curves 15 and 16 store the reference frequency in millihertz. When using the DCB
command (although not with the other curve transfer commands), both curves need to
be transferred separately. They should then be converted to two arrays of integer
values, allowing for the fact that the data points in curve 15 are unsigned 16-bit
values, while those in curve 16 are signed 2's complement 16-bit values (although in
practice they are never negative). Finally they should be assembled into a single
curve using the following algorithm:
Reference Frequency = (65536 × value in Curve 16) + (value in Curve 15)
The computer program's subroutine which reads the responses to the DCB command
needs to be able to handle the potentially very large data blocks (64 k bytes in the
case of one 32 k curve) that can be generated.
NOTE: When using RS232 communications, the interface must be set to use 8 data
bit transmission.

6.4.10 Computer Interfaces (RS232 and GPIB)

RS [n [n ]] Set/read RS232 interface parameters
1 2
The value of n sets the baud rate of the RS232 interface according to the following
1
table:
n Baud rate (bits per second)
1
0 75
1 110
2 134.5
3 150
4 300
5 600
6 1200
7 1800
8 2000
9 2400
10 4800
11 9600
12 19200
The lowest five bits in n
following table:
bit number bit negated
0 data + parity = 8 bits
1 no parity bit
2 even parity
3 echo disabled
4 prompt disabled
Chapter 6, COMPUTER OPERATION
control the other RS232 parameters according to the
2
bit asserted
data + parity = 9 bits
1 parity bit
odd parity
echo enabled
prompt enabled
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