Introduction; Probing Information; How To Prepare The Probe For Use; Input Voltage Levels Of The Probe - IBM System/34 Maintenance Manual

02-010
INTRODUCTION
The general reference information in this section
includes the following:
• Instructions on how to test and use the IBM General
Logic Probe II.
Signal levels used in System/34 logic circuits.
• Locations of optional features on the System/34.
• Additional information needed for servicing the
System/34.
02-015
PROBING INFORMATION
When using the MAPs, use the General Logic Probe II
(IBM part 453212) to determine if a signal level is Up or
Down. Use this probe instead of an oscilloscope for
most System/34 maintenance. Additional information
about using and maintaining this probe is in the
IBM
General Logic Probe II Manual, SY27 -0127.
PIN 5500900
MULTI
~
MST 214 -
MST 1
LATCH
UP~
NONE. -
DOWN
GATE REF
'1.4V~
GND -
··1.3V
GATING
02-020
How to Prepare the Probe for Use
To make the probe ready for use, do the following:
• Set the TechnolQgy switch to the Multi position.
• Set the Latch switch to the None position.
• Set the Gate Ref switch to +1.4V.
• Attach the red lead to any convenient +5V pin (003).
• Attach the black lead to any convenient ground pin
(008).
02-025 Input Voltage Levels of the Probe
When you use the General Logic Probe II with the
Technology switch set to Multi, you can probe voltage
levels as shown in the figure that follows.
General Logic Probe II Input Voltage Ranges
MPUL (+60V) (most positive up level)
LPUL (+2.16V
±
.180V) (least positive up level)
(most positive down level)
MPDL (+.95V
±
.180V)
OV
(least positive down level)
LPDL (·60V)
Indicating Lights
Region Up
Down
I
ON OFF
OFF OFF
OFF ON
VTL and Dutchess Input Voltage Ranges
02-035 What the Probe Lights Mean
The probe lights can have different meanings that rely
on the condition of the lights. Some of the possible
conditions and their meanings are shown in the table
that follows.
2
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