Model 2790 SourceMeter® Switch System User’s Manual 2-13Opening and closing channelsMultiple channel operations are used to control 7751, 7752, and 7753 channels:• Only the specified channels are opened or closed. Unspecified channels are notaffected.• Relays to connect signals to the backplane (DMM) of the Model 2790 do not closeautomatically. You must explicitly close them to perform a measurement. Forexample, with a DUT connected to channel 1 of a 7751, 7752, or 7753 module, youwould have to close channels 1, 14, and 18 to measure it with the Model 2790.• Closed channels are not displayed by the Model 2790 while in the normal displaystate. Closed channels can be viewed from the VIEW item of the CARD menu (see“Viewing closed channels” for details).To control the appropriate switching module, the slot number must be included with theswitching module channel number. The channel assignment is formatted as follows:SCH where: S is the slot number (1 or 2)CH is the channel numberExamples: 101 = Slot 1, Channel 1218 = Slot 2, Channel 18NOTE Interlock of the 7751/7752/7753 must be enabled in order to close channel 18,19, or 21 and open channel 20. See “Open interlock errors” for errors associ-ated with open interlock and see “Interlock” in Section 5 for details on using theinterlock.Front panel operationAs shown in Figure 2-4, the OPEN and CLOSE keys are used to control 7751, 7752, and7753 channels:After closing or opening a single channel:• A message indicating the action (i.e., “101 CLOSED”) will be displayed briefly.• To close another channel, simply key in the channel number and press ENTER.• Press EXIT to exit from the open/close menu structure.NOTE The edit keys (left, right, up, and down arrow keys) are used to display a channelnumber. Pressing ENTER opens or closes the channel.
