[SENSe:]DIGital:HANDshake:THReshold
Syntax
[SENSe:]DIGital:HANDshake:THReshold {<voltage>|MIN|MAX|DEF}, (@<ch_list>)
[SENSe:]DIGital:HANDshake:THReshold? [{MIN|MAX},] (@<ch_list>)
Description
This command sets the input threshold voltage for the H2 handshake line on the specified bank on the 34950A Digital I/O Module. 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).
This command also sets the input threshold voltage for the INTR (interrupt) line on the specified bank. The INTR line is an input when the specified channels are configured for buffered memory output operations (see SOURce:DIGital:MEMory:ENABle command).
Used With:
34950A Digital I/O Module
Parameters
|
Name |
Type |
Range of Values |
Default Value |
|
<voltage> |
Numeric |
Desired threshold voltage between 0V and 5V, with 20 mV resolution. MIN = 0V, MAX = 5V |
0.8V (TTL) |
|
<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 output operations are enabled (see SOURce:DIGital:MEMory:ENABle command).
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 threshold voltage is stored in volatile memory and will be set to 0.8V when power is turned off or after a Factory Reset (*RST command).
Return Format
The query command returns the threshold voltage in the form "+1.00000000E+00" for each channel specified. Multiple responses are separated by commas.
Examples
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, a software trigger is used to trigger the memory output. Once the trace pattern is configured and assigned to the channel, the handshake threshold voltage is set to 1.8V.
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
DIG:HAND:THR 1.8,(@3101)
!Set handshake
threshold voltage to 1.8V
SOUR:DIG:MEM:START (@3101) !Trigger
memory output
The following query returns the threshold voltage settings on channel 101 on the module in slot 3.
DIG:HAND:THR? (@3101)
Typical Response: +1.80000000E+00