CONNECTOR PIN WIRING
The mating connector, if purchased,
should be NLS part # N39-282.
Connection to PC-40 is as follows:
Lower Contacts A Upper Contacts B
Carry Output 1110°Dec Pt.
Zero Suppress 2210¹Select
Reset 3310²& Data
N/C 4410³Strobe
N/C 55Latch Enable
MUX "1" 66N/C
BCD "2" 77N/C
Data "4" 88 Up/Down
Out "8" 99N/C
Count Input 10 10 Up/Down
Blank/Intensity 11 11 N/C
Overflow Out 12 12 N/C
Decimal Com. 13 13 N/C
SIG LO & 14 14 +5VDC
COMMON 15 15 POWER
OPERATION
POWER SUPPLY: Connect negative side
of power supply (Gnd) to pins A14 and A15
of connector and the positive side (+5VDC ±
5%) to pins B14 and B15. Even though the
current requirements of the PC-40 are low
(150 mA maximum @ 5VDC), redundant
contacts are used to enhance the reliability
of the connection.
COUNT INPUT: Connect signal input to
pins A10 and A14 or A15. Signal LO should
go to A14 or A15 and Signal HI should go to
pin A10. Input impedance is 100 KΩ.
Count Up: To count up connect pin
B10 to +5VDC
& B8 to A1
Count Down: To count down connect pin
B10 to Ground
& B8 to Ground
The PC-40 counts a pulse during the
positive-going part of the pulse or when a
contact made to ground is closed. Using
pulse or contact-closure inputs, the
maximum input rate is 50 per second. The
input signal may vary from zero to +3 - +15
volts in amplitude. When using voltage level
input with no contact bounce, the PC-40 will
operate at speeds up to 1,000,000 per
second. To achieve this speed, capacitors
C1, C2 and C3 must be removed from the
main board assembly.
To remove the capacitors, perform the
following steps:
1. Insert the blade of a small screwdriver or
pen knife between case and rear cover,
midway on case above printed circuit
connector, and pry gently outward.
Remove Cover.
2. Slide counter assembly from case.
Observe that red filter is now a loose
piece and will
be required for reassembly.
3. C1, C2 and C3 are the rear most three
capacitors on the main board assembly.
Unsolder leads and remove capacitors.
4. Reassemble meter.
RESET: A negative going pulse or a
contact closure to ground will cause a reset
of the counter. If a pulse is used the duration
must be at least 20 mSec, or with filter
removed at least 1 µSec.
DECIMAL POINT AND DATA
STROBE: If a decimal point is desired,
jumper between pin A13 and pins B1, B2,
B3 or B4 depending upon which decimal
point is to be illuminated. If a decimal point
is not desired, jumper pin A13 to pin B14.
Decimal Location . X . X . X . X
Pin Number B4 B3 B2 B1
As a data strobe, the true state is low. When
one of the four strobe lines is low, it means
that the four multiplexed BCD data output
lines are presenting the BCD code as an
output for the decade indicated by that
strobe line.
BCD OUTPUTS: The outputs of the MUX
BCD data output lines, pins A6, A7, A8 and
A9, are the 1-2-4-8 BCD bits for the four
digits. True is a high state. The decimal point
and data strobe lines described above are
used to decode the multiplexed data output.
The decimal point data output is obtained by
connection to the decimal point data is
decoded with the data strobe lines. For the
decimal point location, data output true is
low. An overflow indication is provided at pin
A12: true is high.
The MUX BCD outputs are as follows:
(nominal values)
BCD Data Decade Strobe
True-High True-Low
Frequency 600 Hz 150 Hz
Pulse Width 1500 µS 6000 µS
Voltage +5V +5V
Allowable CMOS 1 T²L
Loading (CMOS Preferred)
CARRY OUTPUT: On pin A1, an output
is provided which will permit the user to
cascade PC-40's. This output goes to +5
volts on the count of 9999. On the next pulse
input the voltage goes low. Allowable
loading is one CMOS load.
ZERO SUPPRESSION:If desired, the
zeros to the left of a significant digit can be
suppressed. to do so, leave pin A2 open. To
display all numbers, ground pin A2.
BLANKING/INTENSITY CONTROL: It
is possible to shut off the display or control
its intensity while operating in a count mode.
Pin A11 must be connected to +5VDC ±5%
for the display to be on. Placing a switch in
the line permits display on-off. A variable
resistor permits control if intensity.
Recommended resistance is 0 to 1 KΩ.
Maximum current is 150 mA @ 5 volts.
LATCH ENABLE: Connecting pin B5 to
ground causes the display to follow the
input. Each input pulse will be counted and
displayed. An open or no connection results
in the display of the number in the counter at
the time of the opening of the line.
Reconnection to ground causes an update
of the data to the then present number on
the counter. This function holds for total
counts to 9999.
CALIBRATION: Calibration is not
required; there are no adjustments in the
counter.
Specifications Subject to Change Without Notice
Thank you for choosing Non-Linear
Systems products. Should you have any
questions please call, fax or visit our
Website at nonlinearsystems.com
NON-LINEAR SYSTEMS
Originator of the Digital Voltmeter
San Diego, CA
Phone: (619) 521-2161
Fax: (619) 521-2169
Email: sales@nonlinearsystems.com
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