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

Front Panel Operation3. Interlocked channels can be scanned as long as only onechannel is closed at a time. However, if a scan is performedwhile a channel is left closed, any channels inthe scan list that are interlocked to the closed channelwill be skipped when the scan is performed.4. If a channel is closed, you can enter a channel that is interlockedto it into the scan list but the “Forbidden channelerror” message will occur to indicate that it will notbe scanned (see note 3).5. If you specify channels to be interlocked, and they arealready included in the Scan List and/or a Channel Pattern(interlock violation), a saved state error (+510) occursand the entire Scan List and/or Channel Pattern iscleared (lost). For example, if the Scan List includeschannels 1!1 and 1!2, and you specify those two channelsto be interlocked (1!1 in List A and 1!2 in List B),then the Scan List is cleared. See paragraphs 4.8 and4.11 for more information.4.15 Digital I/O portThe Model 7002’s Digital I/O port is a 9-pin D- sub-miniatureconnector (J1006) located on the rear panel. The portslocation and pin designations are shown in Figure 4-13.The Model 7002’s Digital I/O port can be used to control externalcircuitry. The port provides four output lines and oneinput line. Each open-collector output can be set high (+5V)or low (0V) and will sink up to 100mA. The four output linescan also operate external supplies from +5V to +30V.Use the DIGITAL I/O MENU to select the following options(information on each menu item is contained in paragraph4.12.3):• OUTPUT-STATUSON or OFF selectable for each output line (1 through4). Use this option to check or change the output state.For example, the following OUTPUT-STATUS displayis set to ON for digital output #1 and OFF for outputs#2 through #4:DIGITAL OUTPUT LINES1=ON 2=OFF 3=OFF 4=OFFChanging the display to the following turns digital output#1 to OFF and output #2 to ON. Outputs #3 and #4remain OFF.DIGITAL OUTPUT LINES1=OFF 2=ON 3=OFF 4=OFF• OUTPUT-POLARITYTRIGGERLINKDIGITAL I/OINOUTACTIVE-HIGH or ACTIVE-LOW selectable for eachoutput line (TTL1 through TTL4). Use this option tocheck or change the logic sense. Select the desired outputline (TTL1 through TTL4), and check or change theoutput-polarity. For example, the following shows thedisplay used to check or change TTL3 (digital output#3):SELECT OUTPUT LINETTL1 TTL2 TTL3 TTL49561Digital I/OReceptacleFigure 4-13Digital I/O port1 = Digital Input2 = (+5V)3 = N/C4 = External Voltage Flyback connection5 = Digital Ground6 = Digital Output #17 = Digital Output #28 = Digital Output #39 = Digital Output #4Selecting TTL3 and pressing ENTER changes the displayto:TTL3 LOGIC SENSEACTIVE-HIGH ACTIVE-LOWACTIVE-HIGH is the current setting for digital output#3.4-53