12-Edge Output Jitter Measurement Commands
The PAM4 12-Edge Output Jitter measurements are designed for the IEEE 802.3bs standard. When making these measurements, the standard calls for using a PRBS13Q pattern. These measurements are not designed to work on NRZ signals. The commands listed in this topic turn on the Jnu, Jrms, and EOJ IEEE measurements and view the results in the Output Jitter panel as shown in this picture.
To expand or contract the listing for Jnu, Jrms, and EOJ measurements in the panel, use the :DISPlay child commands. For example,
:MEASure:JITTer:OJITter:JNU:DISPlay
When measurement results are expanded in the panel, results are shown for each of 12 edge transitions plus the measurement for all transitions. This is shown in this picture for J4u. Since the Jrms and EOJ listings in the picture are contracted, the 12 edge transitions are hidden and you cannot return their measurements until you expand them. However, you can still return the measurement for all transitions. The listing must be expanded before you can return measurement results.
Use the :MEASure:JITTer:OJITter:JNU:ECATegory child command to select an edge transition for which you want to return the measurement result using the parent query. Use the :MEASure:JITTer:OJITter:SJNU command to select the Jnu type. For example, these commands return the J4u results for the rising level 0 to level 3 edge transition:
:MEASure:JITTer:OJITter:JNU:ECATegory R03 :MEASure:JITTer:OJITter:SJNU J4U :MEASure:JITTer:OJITter:JNU:DISPlay ON :MEASure:JITTer:OJITter:JNU?
Use the child :LOCation? queries to return an index string that identifies the location in the panel of results for a selected edge-category transition. This index is used for the following tasks:
- To select a measurement for measurement limit testing.
- To select a measurement to publish to an N8844A data analytics server.
Output Jitter Output Jitter Histogram (PAM4 only)
These queries return output jitter histogram data.