1256E User Manual
Racal Instruments
©
2002
Digital Module Operation 7-9
Setting Up the
Synchronous Test
The DIGITAL:SYNCHRONOUS:DATA command is used to load
data into the memory of the 1260-114. This defines the data that
will be clocked out, one byte per CLKIN pulse.
Each synchronous output port may hold up to 256 data bytes.
Each byte may have a value between 0 and 255. Each time the
DIGITAL:SYNCHRONOUS:DATA command is executed, new data
bytes are added to any data that was previously downloaded.
For example, the commands:
DIG:SYNC:DATA (@7(4)),10,11,12
DIG:SYNC:DATA
(@7(4)),50,60,70,80,90
DIG:SYNC:DATA
(@7(4),255,254
are equivalent to the command:
DIG:SYNC:DATA(@7(4)),10,11,12,50,60,70,80,
90,255,254
The DIGITAL:SYNCHRONOUS:INDEX command provides
flexibility for loading new data to output. This command sets the
location at which the next DIG:SYNC:DATA command will
download.
The value passed as the <index> for this command must satisfy
the following conditions:
Minimum value:
0
Maximum value:
255, but less than, or equal to, the
number of data points loaded
Figures 7-1 (A-D) show the interaction between the
DIG:SYNC:DATA command and the DIG:SYNC:INDEX command.
After power-on, or a *RST command, no data is loaded into any
output port buffer of a 1260-114. The index for each port points to
the first location in the buffer.
After executing the command:
DIG:SYNC:DATA
(@7(4)),10,20,30,40
the memory buffer for port 4 of module 7 is filled with data as
depicted in Figure 7-1 (A). There are four bytes loaded. The index
for this port points to the next available position in the port buffer,
shown as location 4 in the figure.
