Model 7002Switch System Instruction Manual - Advanced Test ...

Front Panel OperationArm layerNOTEThe arm layer is programmed from theSETUP ARM CONTROL menu (see paragraph4.14.3).In general, the instrument requires an arm event to allow operationto proceed to the next layer (scan layer). With Immediatearm spacing selected, operation immediately proceedsto the next layer when the instrument is taken out of the idlestate. RESET and factory defaults set arm spacing to Immediate.With one of the other arm spacing events selected, theinstrument waits until the appropriate event occurs.• With Manual arm spacing selected, the instrumentwaits until the front panel STEP key is pressed.• With GPIB arm spacing selected, the instrument waitsfor a bus trigger (GET or *TRG).• With External arm spacing selected, the instrumentwaits for an input trigger via EXTERNAL TRIGGERon the rear panel.• With TrigLink arm spacing selected, the instrumentwaits for an input trigger via TRIGGER LINK on therear panel.• With Hold arm spacing selected, the instrument doesnot respond to any of the arm spacing events.As can be seen in the flowchart, there is a path that allows operationto loop around the programmed spacing event. Thispath is called the Source Bypass. When the Source Bypass isenabled (Arm Trigger Control set to Source) and External orTrigLink arm spacing is selected, operation loops around thespacing event on the initial pass through the arm layer. If programmedfor another arm (arm count >1), the bypass loop isnot in effect even though it is enabled. The Source Bypassloop resets (back in effect) when operation goes into Idle.Enabling the Source Bypass also enables the Output Triggerin this layer. When operation returns to the arm layer fromthe scan layer, an output trigger pulse occurs. If TrigLink armspacing is selected, the output trigger pulse is available onthe programmed TRIGGER LINK output line. For all otherarm spacing selections, the output trigger pulse is availableat the CHANNEL READY connector. The output trigger forthis layer is disabled when the Source Bypass is disabled(Arm Trigger Control set to Acceptor). RESET and factorydefaults set Arm Trigger Control to Acceptor.After all other trigger model operations are completed, theModel 7002 can be returned to the arm layer by programmingthe instrument for additional arms. Arm Count can beset to infinity or to a finite value (1 to 9999). RESET and factorydefaults set arm count to one.After leaving the arm layer, operation proceeds into the scanlayer.Scan layerNOTEThe scan layer is programmed from theSCAN CONTROL menu (see paragraph4.14.2).Operation in the scan layer is similar to operation in the armlayer, except that spacing is controlled by scan events ratherthan arm events. A timer is available in this layer to controlscan spacing. When Timer scan spacing is selected, operationwill immediately proceed into the channel layer on theinitial pass through the scan layer. Each additional scan (1 to9999 or infinite) will not occur until the programmed timerinterval elapses. The timer can be set to an interval from1msec to 99999.999 seconds.The Source Bypass and Output Trigger function in the samemanner as the Source Bypass and Output Trigger in the armlayer. The Source Bypass (if enabled) will reset (back in effect)after all programmed scans are completed.RESET and factory defaults set scan spacing to Immediate,scan count to infinite and Scan Trigger Control to Acceptor.After leaving the scan layer, operation proceeds into thechannel layer.4-22