INITiate
INITiate
Syntax
INITiate
Description
This command changes the state of the triggering system from the "idle" state to the "wait-for-trigger" state. Scanning will begin when the specified trigger conditions are satisfied following the receipt of the INITiate command. Readings are stored in the instrument's internal reading memory. Note that the INITiate command also clears the previous set of readings from memory.
If a scan list is currently defined (see ROUTe:SCAN command), the INITiate command performs a scan of the specified channels.
If a scan list is not currently defined, the INITiate command fails.
Remarks
- Storing readings in memory using the INITiate command is generally faster than sending readings to memory using the READ? command. The INITiate command is also an "overlapped" command. This means that after executing the INITiate command, you can send other commands that do not affect the measurements.
- You can store up to 50,000 readings in memory and all readings are automatically time stamped. If memory overflows, the new readings will overwrite the first (oldest) readings stored; the most recent readings are always preserved. In addition, bit 9 is set in the Questionable Data Register's condition register (see Status System Introduction).
- For scanning measurements using the multiplexer modules, an error is generated if the internal DMM is disabled (see INSTrument:DMM command) or not installed in the mainframe. The internal DMM is not required for operations on the digital modules.
- If a scan list containing multiplexer channels is currently defined (see ROUTe:SCAN command), the INITiate command performs a scan of the specified channels. When the scan is initiated, the instrument will open all channels in banks that contain one or more channels in the scan list.
- The instrument scans the list of channels in ascending order from slot 100 through slot 300 (channels are re-ordered as needed).When you specify a range of channels in the <scan_list>, the channels are always sorted in ascending order. Therefore, (@109:101) will always be interpreted as 101, 102, 103, etc.
- Once you initiate a scan, an error will be generated if you attempt to change any measurement parameters (CONFigure and SENSe commands) or the triggering configuration (TRIGger commands). To abort a scan in progress, send the ABORt command.
- To retrieve the readings from memory, use the FETCh? command. The readings are not erased from memory when you read them. You can send the command multiple times to retrieve the same data in reading memory.
Example
The following program segment shows how to use the INITiate command with the CONFigure and FETCh? commands. The ROUTe:SCAN command puts the two channels into the scan list (and redefines the scan list). The INITiate command places the instrument in the "wait-for-trigger" state, scans the specified channels when the rear-panel Ext Trig Input line is pulsed low, and then sends the readings to memory. The FETCh? command transfers the readings from memory to the instrument's output buffer.
CONF:VOLT:DC 10,0.003,(@103,108)
ROUT:SCAN (@103,108)
TRIG:SOUR EXT
INIT
FETC?
Typical Response: +4.27150000E-03,+1.32130000E-03
See Also