CONFigure:DIGital:HANDshake:POLarity
Syntax
CONFigure:DIGital:HANDshake:POLarity <polarity>, [{<line>|ALL},] (@<ch_list>)
CONFigure:DIGital:HANDshake:POLarity? <line>, (@<ch_list>)
Description
This command sets the logic polarity of one or all of the three handshake lines (H0, H1, and H2) on the 34950A Digital I/O Module. You can specify the polarity as "normal" (active high, default) or "inverted" (active low). The specified setting affects the polarity for both input and output modes of the INTR lines on the specified bank. Since handshaking is used for transfers involving the first channel on a bank only, this command must be directed to the first channel (i.e., channel 101 or 201 only), and extends to all channels involved in the channel width (see CONFigure:DIGital:WIDTh command).
|
|
The handshake lines and the INTR (interrupt) lines on each bank share their polarity. |
Used With:
34950A Digital I/O Module
Parameters
|
Name |
Type |
Range of Values |
Default Value |
|
<polarity> |
Discrete |
{NORMal|INVerted} |
NORMal (active high) |
|
<line> |
Discrete |
{H0|0|H1|1|H2|2|ALL} |
ALL |
|
<ch_list>
|
Numeric
|
The first channel on a bank in the form (@sccc).
|
This is a required parameter
|
Remarks
-
The behavior of the three handshake lines depends on whether buffered memory input/output operations are enabled (see [SENSe:]DIGital:MEMory:ENABle and SOURce:DIGital:MEMory:ENABle commands).
H0 Line
H1 Line
H2 Line
Unbuffered Transfers
I/O Direction (output)
Strobe (output)
Not Used (Hi-Z)
Buffered Transfers
Start/Stop (output)
Strobe (output)
Input Strobe (input)
If desired, you can use the CONFigure:DIGital:HANDshake command to select all of the handshake line parameters with one command. Use this command to select the input threshold voltage, output logic "1" voltage level, and logic polarity.
The selected polarity is stored in volatile memory and will be set to "NORM" when power is turned off or after a Factory Reset (*RST command).
Return Format
The query command returns "NORM" or "INV" for the specified channels. Multiple responses are separated by commas.
Examples
The following program segment selects an inverted polarity (active low) for handshake line H0 (Bank 1) on the module in slot 3.
CONF:DIG:WIDTH WORD,(@3101) !Width
= 16 bits
CONF:DIG:HAND:POL INV,(@3101)
The following query returns the polarity of handshake line H0 (Bank 1) on the module in slot 3.
CONF:DIG:HAND:POL? (@3101)
Typical Response: INV
See Also
CONFigure:DIGital:HANDshake:DRIVe
[SENSe:]DIGital:HANDshake:THReshold