SOURce:DIGital:MEMory:STARt
Syntax
SOURce:DIGital:MEMory:STARt (@<ch_list>)
Description
This command starts buffered (memory) output operations on the 34950A Digital I/O Module. If memory is currently disabled (see SOURce:DIGital:MEMory:ENABle command), this command will enable memory and start the buffered write. The width of the first channel in each bank (i.e., channels 101 and 201) controls the width of the memory operations (64K x 8 Bits, 64K x 16 Bits, or 32K x 32 Bits). The first channel on the specified bank must be configured as an output prior to starting a buffered write (see SOURce:DIGital:DATA[:<width>] command) and a trace must be downloaded to memory and assigned to the specified bank (see SOURce:DIGital:MEMory:TRACe command).
Used With:
34950A Digital I/O Module
Parameters
|
Name |
Type |
Range of Values |
Default Value |
|
<ch_list> |
Numeric |
The first channel on a bank in the form (@sccc).
|
This is a required parameter |
Remarks
Depending on the width specified (see SOURce:DIGital:DATA[:<width>] command), the channel numbering is modified as shown below. For example, if you specify the width as a 16-bit WORD, channels 101 and 102 are combined and addressed collectively as channel 101.
|
|
Bank 2 |
Bank 1 |
||||||
|
BYTE (8 Bits): |
Ch 204 |
Ch 203 |
Ch 202 |
Ch 201 |
Ch 104 |
Ch 103 |
Ch 102 |
Ch 101 |
|
WORD (16 Bits): |
Ch 203 |
Ch 201 |
Ch 103 |
Ch 101 |
||||
|
LWORd (32 Bits): |
Ch 201 |
Ch 101 |
||||||
You can also use this command to resume a stopped buffered write (see SOURce:DIGital:MEMory:STOP command).
You can use the SOURce:DIGital:MEMory:ABORt command prior to sending the SOURce:DIGital:MEMory:STARt command to restart the buffered write from the beginning.
This command overrides the hardware INTR (interrupt) line (see SOURce:DIGital:INTerrupt[:ENABle] command); therefore, you can use the SOURce:DIGital:MEMory:STARt command to start the buffered write even if the bank is configured to start on an interrupt.
If you send this command while a buffered write is already running, additional SOURce:DIGital:MEMory:STARt commands are ignored (no error is generated).
Example
The following program segment downloads and outputs a "walking ones" pattern from channel 101 on the module in slot 3. The length of the trace is set to 32 samples. In addition, the cycle count is set to output the complete trace three times. Once memory is enabled, the SOURce:DIGital:MEMory:STARt command is used to trigger the memory output.
SOUR:DIG:DATA:WORD
#HFFFF,(@3101) !Set
initial output pattern
SOUR:DIG:MEM:NCYC 3,(@3101) !Output
complete trace 3 times
TRAC:DIG:FUNC (@3101),WONES,PATTERN_1,32 !Download
"walking ones" pattern
SOUR:DIG:MEM:TRAC PATTERN_1,(@3101) !Assign
trace to channel 101
SOUR:DIG:MEM:ENAB ON,(@3101) !Enable
memory on channel 101
SOUR:DIG:MEM:START (@3101) !Trigger
memory output
See Also
SOURce:DIGital:INTerrupt[:ENABle]
SOURce:DIGital:MEMory:ABORt
SOURce:DIGital:MEMory:NCYCles
SOURce:DIGital:MEMory:TRACe