MEASure:DIGital?
Syntax
MEASure:DIGital? <width>, [<voltage>,] [<polarity>,] (@<ch_list>)
Description
This command configures the specified channels for unbuffered (no memory) input operations and immediately sweeps through the specified channels one time (independent of the present scan list). The results are sent directly to reading memory and the instrument's output buffer.
Used With:
34950A Digital I/O Module (digital input channels only)
34952A Multifunction Module (digital input channels only)
34959A Breadboard Module (digital input channels only)
Parameters
|
Name |
Type |
Range of Values |
Default Value |
|
<width> |
Discrete |
{BYTE|1|WORD|2|LWORd|4} BYTE (or "1" byte): 8
bits 34959A: Only valid configurations are BYTE/WORD. |
This is a required parameter |
|
<voltage>1
|
Numeric |
Desired threshold voltage between 0V and 5V, with 20 mV resolution. MIN = 0V, MAX = 5V |
0.8V (TTL) |
|
<polarity>2 |
Discrete |
{NORMal|INVerted} |
NORMal (active high) |
|
<ch_list>
|
Numeric
|
One or more digital input or output channels in the form (@sccc). 34950A: s101
through s104, s201 through s204 |
This is a required parameter
|
| 1 Variable threshold voltage is available only on the 34950A. 2 Variable polarity is available only on the 34950A and 34952A. |
|||
Remarks
By default, the instrument scans the list of channels in ascending order from slot 1 through slot 8 (channels are reordered as needed). If your application requires non-ordered scanning of the channels in the present scan list, you can use the ROUTe:SCAN:ORDered command to enable the non-sequential scanning mode. In either mode, channels which are not in the scan list are skipped during the scan.
When you specify a range of channels with this command, any channels that are invalid will be ignored (no error will be generated) but the first and last channel in the range must be valid for the selected function.
If this command is directed to the first channel on a bank on the 34950A (i.e., channel 101 or 201) this command will reset all handshaking parameters (see CONFigure:DIGital:HANDshake command) and the buffered memory mode will be aborted and disabled.
Changing the channel width will disable buffered (memory) operations and clear memory on the specified digital channels (see [SENSe:]DIGital:MEMory:ENABle command).
The *RST command will clear the scan list and set all measurement parameters to their factory settings. The Instrument Preset (SYSTem:PRESet command) will not clear the scan list; however, this command will clear reading memory.
Return Format
This command returns a decimal value representing the bit pattern on each digital input channel specified. Multiple responses are separated by commas. The output from this command is affected by the settings of the FORMat:READing commands.
Examples
The following command configures the 34950A in slot 3 for two 16-bit words, selects an "active low" polarity (the optional threshold voltage parameter is omitted in this example), triggers the module to read the channels one time, and then transfers the readings to reading memory and the instrument's output buffer.
MEAS:DIG? WORD,INV,(@3101,3103)
Typical Response: 65487,64972
The following command configures the 34952A in slot 5 for one 32-bit word, selects an "active high" polarity, triggers the module to read the channel one time, and then transfers the reading to reading memory and the instrument's output buffer.
MEAS:DIG? LWORD,NORM,(@5001)
Typical Response: 529755