CALCulate:LIMit:LOWer:STATe
CALCulate:LIMit:LOWer:STATe
CALCulate:LIMit:UPPer:STATe
Syntax
CALCulate:LIMit:LOWer:STATe <mode>,(@<ch_list>)
CALCulate:LIMit:LOWer:STATe? (@<ch_list>)
CALCulate:LIMit:UPPer:STATe <mode>,(@<ch_list>)
CALCulate:LIMit:UPPer:STATe? (@<ch_list>)
Description
These commands disable or enable the lower and upper alarm limits on the specified multiplexer channels.
Used With:
- 34901A 20 Channel Multiplexer (2/4-wire) Module
- 34902A 16 Channel Multiplexer (2/4-wire) Module
- 34908A 40 Channel Single-Ended Multiplexer Module
Parameters
Name Type Range of Values Default Value <mode> Boolean {OFF|0|ON|1} OFF <ch_list> Channel List One or more channels, as shown:
(@310) - channel 10 on the module in slot 300.
(@305:310) - channels 05 through 10 on the module in slot 300.
(@202:207,209,302:308) - channels 02 through 07 and 09 on the module in slot 200 and channels 02 through 08 on the module in slot 300.
If you omit the optional <ch_list> parameter, this command applies to the currently defined scan list.
Remarks
- Alarm data can be stored in one of two locations depending on whether a scan list is running when the alarm occurs.
- If an alarm event occurs on a channel as it is being scanned, then that channel's alarm status is stored in reading memory as the readings are taken. Each reading that is outside the specified alarm limit is logged in memory. You can store at least 50,000 readings in memory during a scan.
- As alarm events are generated, they are also logged in an alarm queue, which is separate from reading memory. This is the only place that non-scanned alarms get logged (alarms during a channel monitor, alarms generated by the digital modules, etc.). Up to 20 alarms can be logged in the alarm queue. If more than 20 alarm events are generated, they will be lost (only the first 20 alarms are saved). Even if the alarm queue is full, the alarm status is stored in reading memory during a scan.
- Alarms are evaluated during a scan or a monitor measurement on channels of a multiplexer module. For scanning using a multiplexer module, 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 and the specified channels do not have to be part of the active scan list to generate an alarm.
- When an alarm occurs, the instrument stores relevant information about the alarm in the queue. This includes the reading that caused the alarm, the time of day and date of the alarm, and the channel number on which the alarm occurred. The information stored in the alarm queue is always in absolute time and is not affected by the FORMat:READing:TIME:TYPE command setting.
- Alarms are logged in the alarm queue only when a reading crosses a limit, not while it remains outside the limit and not when it returns to within limits.
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In addition to being stored in reading memory, alarms are also recorded in their own SCPI Status System. You can configure the instrument to use the status register to generate a Service Request (SRQ) when alarms are generated. For more information on the Status System for the instrument, see Status System Introduction.
On the digital modules, you can set an upper limit for the totalizer channels (no lower limit is allowed). These channels do not have to be part of the active scan list to generate an alarm, but alarm data is stored in reading memory only as part of a scan.
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To generate an alarm when a specific count is reached on a totalizer channel, see the CALCulate:LIMit:UPPer command. To generate an alarm when a specific bit pattern or bit pattern change is detected on a digital input channel, see the CALCulate:COMPare commands.
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The instrument clears all alarm limits and turns off all alarms after a Factory Reset (*RST command), Instrument Preset (SYSTem:PRESet command), or Card Reset (SYSTem:CPON command).
Return Format
The query returns 0 (OFF) or 1 (ON) for each channel specified. Multiple responses are separated by commas.
Examples
In the examples below, you can replace the node name UPP with LOW.
The following program segment sets an upper limit on channels 03 and 13 in slot 100 and then enables alarms on these channels.
CALC:LIM:UPP 10.25,(@103,113)
CALC:LIM:UPP:STAT ON,(@103,113)
The following query returns the state of upper limits on channels 03 and 13 in slot 100.
CALC:LIM:UPP:STAT? (@103,113)
Typical Response: 1,1
The following command sets the upper limit to 4095 on totalizer channels 01 and 02 in slot 300 and then enables alarms on these channels.
CALC:LIM:UPP 4.095E+03,(@301,302)
CALC:LIM:UPP:STAT ON,(@301,302)
See Also
CALCulate Subsystem Introduction