Indicator Lights; Counter Display Rotary Switch; Decimal Digit Display; Connecting Th E Monitor Probes - IBM 360 Manual

Indicator Lights

Punch Ready
Count Enable
Intfc Check
Test Mode
Punch Ready indicates that the IBM 1057/1058 Card
Punch is ready to accept data from the Basic Counter Unit.
Count Enable signifies that timing and counting signals are
being accepted by the Basic Counter Unit. This indicator
light is activated by the start switch. The light is turned off
when either the stop hub is activated or the stop switch or
machine reset switch is pressed.
Intfc Check (Interface Check) denotes that an error has
occurred during a counter select sequence of a card punch
operation or during a data transfer between the Basic
Counter Unit and the Punch. The light remains on until
check reset or machine reset switch is pressed.
Test Mode is on when the Basic Counter Unit is in test
mode. In this state, the Basic Counter Unit is disabled from
accepting input pulses from any external sources. See
"Appendix F."

Counter Display Rotary Switch

This 16-point (0-15) rotary switch selects the counter to be
displayed on the decimal digit display.

Decimal Digit Display

The decimal digit display (Figure 6), a row of 12 decimal
digit display indicators, shows the static or dynamic
accumulation of any selected counter. The leftmost digit,
backlighted in red, indicates which of the 16 counters has
been selected for display by the counter display rotary
switch. The remaining 11 digits display the decimal value of
the selected counter.
Figure 6. Decimal Digit Display
IBM Internal Use Only

CONNECTING TH E MONITOR PROBES

The following standard accessories are supplied with each
Basic Counter Unit to monitor signals from systems and I/O
devices for measurement:
20 monitor probes with connected monitor probe cables (15 feet
each).
10 monitor probe extension cables (20 feet each).
2 junction boxes.
2 signal cables (50 feet each).

Monitor Probe Description

The Basic Counter Unit connects to a system by using a
specially designed non-interfering monitor probe. Monitor
probes are connected to pin locations on the back panel of
the equipment being monitored. The monitor probe con­
nection procedure is similar to the oscilloscope connection
procedure used by a customer engineer. See IBM 2989
Model 11 Basic Counter Unit, FETOM,ZY27-2236, for the
approved probe attachment points for IBM System/360,
IBM 1800 Data Acquisition and Control System, and IBM
1130 Computing System.
In measuring a system, the Basic Counter Unit requires
data from primary sources or generated sources or both.
A primary source is when the Basic Counter Unit records
data directly from the system to which the monitor probes
are attached. Primary sources are listed in "Appendix A"
under ALD.
A generated source is when the Basic Counter Unit uses a
combination of primary sources through its combinatorial
(Boolean) logic on the patch panel. Generated sources are
listed in "Appendix B" under Combinatorial Logic.
The monitor probe is a high-impedance differential input
device that is suitable for monitoring signal lines in most
IBM circuit families without disturbing the normal opera­
tion of the circuit.
The probe contains a miniature differential amplifier,
which is capable of detecting a voltage change from a
reference voltage. A voltage at one level during one state
(CPU active) will change when the state changes (CPU
wait). The differential amplifier in the probe detects this
voltage change and drives a signal to the Basic Counter
Unit. The operating power for the monitor probe is
obtained from the Basic Counter Unit.
Each probe consists of a module with six protruding wires
(Figure 7). Supplied with the probes are adapters that
slip on to allow attachment to the pins on the systems or
I/O devices being monitored. An example o f the IBM
Basic Counter Unit Probe Assignment Planning Form,
ZX22-6946, appears in "Appendix C."
Monitor Probe Cable
The length between the monitor probe and the junction
box is called the monitor probe cable. Each Basic Counter
Operating the IBM Basic Counter Unit 9