Global Specialties PB-502 - Manual - Manual (Page 14)

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b) Amplitude should be +12 volts in CMOS, +5 volts in TTL.
4. In all cases, duty cycle should be between 40% and 60%
Step III
Use a jumper wire to test the Logic Indicators as follows:
1. Jumper CMOS/TTL selector to CMOS.
2. Observe that all 8 LEDS are off.
3. Connect a jumper wire between the Vcc tie point and the L0 tie point.
L0 should light, all other LEDs should remain off.
4. Move the jumper wire from L0 to LI. LI should light, all other LEDs should
remain off.
5. Repeat these steps for L2 through L7.
Step IV
Use jumper wires to test the Seven-Segment Displays as follows:
1. Connect a jumper between DSIDE and +12 V.
a) DS1 should light, showing a 0.
2. Connect a jumper between DS1LT and GND.
a) All segments of DS1 should light.
3. Disconnect the jumper between DS1LT and GND.
a) DS1 should again display a 0.
4. Jumper between DS1A and Vcc.
a) A numeral 1 should be displayed on DS1.
5. Move the jumper from DS1A to DS1B.
a) A 2 should be displayed.
6. Move the jumper from DS1B to DS1C.
a) A 4 should be displayed.
7. Move the jumper from DS1C to DS1D.
a) An 8 should be displayed.
8. Leaving the jumper in DS1D, connect another jumper from DS1LE to Vcc.
a) The 8 should remain on.
9. Remove the jumper from DS1D.
a) The 8 should remain on.
10. Remove the jumper from DS1LE.
a) The display should return to 0.
11. Repeat steps 1-10 for DS2.