mensor PCS 400, Operation Manual

Page: 87 / 118

11 – BCD OUTPUT
The BCD output is accessed through a 36 pin
accessory connector on the rear panel. There are
24 lines of BCD data and two lines for +5 VDC and
ground. This connector and its wiring are identical
to previous Mensor instruments equipped with 24
line BCD output.
The BCD data signals are positive logic, TTL com-
patible, and have a minimum fan-out of one TTL
load. These signals reflect the pressure measured
at the MEASURE/CONTROL port in real time, ex-
cept when BCD INHIBIT (see below) is switched on.
The twenty four lines of BCD data convert to 6
decimal digits, from 0 to 100,000 counts. A BCD
reading of 100000 indicates the full scale pressure
in psi and a reading of 0 indicates minimum pres-
sure. There is no overrange, underrange, decimal
point, nor engineering units associated with BCD
output. The BCD signals are always available at the
connector and are not associated with any GPIB,
or RS-232 functions, nor any menu commands.
Data Ready
In addition to the pressure data lines “Ready” and
“Inhibit” functions are available to the connector.
The Data Ready signal (pin 32) is held low while
the output is being updated, and is high when the
numbers are valid.
Data Inhibit
The Data Inhibit signal (pin 31) is an input from an
external switch closure which will latch the pres-
sure data lines in their current state until released
by the switch. When the Inhibit signal is released
the data lines will immediately update to the cur-
rent psi pressure reading.
Analog Input
The + and – Analog Input pins (pins 33 and 34) are
reserved for the optional Analog Input command
for controlled pressure output.
NOTE:
Direct binary data output is
available as an alternative to BCD data
output.
BCD Output Specifications
Range: 000000 to 999999
Resolution: 0 to 100,000 counts for 0 to full scale
pressure.
Electrical: 24 BCD data lines, LSTTL
compatible.
Fan out =1 TTL load, minimum.
1 line + 5 VDC BCD power.
1 line BCD common
OPTIONS
PCS 400
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