:CMODe Subsystem

The :CMODe subsystem commands control common-mode waveforms in TDR/TDT mode. Common-mode waveforms are not available in any other instrument mode. Common-mode waveforms are most useful when using a TDR Setup configured as a Basic Control Experience where time-domain parameters are not available. You can configure both differential and common mode traces to provide mixed stimulus S-parameters. Before using the commands in this subsystem, the TDR setup must be configured to Differential as the TDR Stimulus Mode. Use the TDR:AMODe command.

Waveform Identification

In the :CMODe command syntax, common-mode waveforms are identified by the associated module slot number (from 1 to 4). For example, the following command sets the color of the common-mode waveform of an N1055A TDR module installed in slots 1 and 2.

:CMODe1A:COLor TCOLor8

Traditional modules take up two module slots, either slots 1 and 2 or slots 3 and 4. For these type of modules, the common-mode waveform is identified using the number for the left-most occupied slot. For example, :CMODe1A or :CMODe3A, respectively. Single-slot modules could have two channels. In this case, the common-mode waveform of a module installed in slot 4 would be identified as :CMODe4. Also, when FlexDCA is configured with a simulated extended module, one-slot simulated modules are available that have two channels. The following table show several examples of common-mode waveform identification.

Examples of Common-Mode Waveform Numbers

Module Type	Installed Slots	Source Channels for Differential Waveform	Differential Channel Waveform Identification
Traditional Two-Slot, Dual Channel (for example, 86112A)	1 & 2	1A and 2A	:CMODe2A
	3 & 4	3A and 4A	:CMODe3A
Simulated or Future Single-Slot, Dual Channel	1	1A and 1B	:CMODe1A
	2	2A and 2B	:CMODe2A
	3	3A and 3B	:CMODe3A
	4	4A and 4B	:CMODe4A

Example Command Sequence

:CMODe1A:DISPlay ON
:CMODe1A:TCOLor 7