4
3.3 POLARITY OUTPUT
This three-state output is active when Digits 1, 2 and 3 are enabled. Signal
polarity can be reversed by a push-on jumper at S4. With a jumper on S4-A, a
high level corresponds to a positive display value.
3.4 DECIMAL POINT BINARY ADDRESS (D.P. 1, 2 AND 4)
These three-state outputs are enabled with Digits 1, 2 and 3. Signal polarity can be
reversed by a push-on jumper at S4. With a jumper on S4-A, the outputs represent
positive true binary address of a right-hand decimal point (see Table 3-2).
Decimal Point Position D.P. 4 D.P. 2 D.P. 1
FFFFFF.
001
FFFFF.F 0 1 0
FFFF.FF 0 1 1
FFF.FFF 1 0 0
FF.FFFF 1 0 1
F.FFFFF 1 1
0
Table 3-2 Decimal Point Binary Address
3.5 OVERFLOW OUTPUT
This three-state output is active when Digits 4, 5 and 6 are enabled. S4 reverses
the polarity. When a jumper is installed on S4-A, an overflow condition makes this
output go high. In this case, all of the digits of the parallel BCD board
represent a "9" (BCD 1001). The decimal point address corresponds to the
point selected as Fixed Range decimal point. S7 connects this output to
pin U22 of the P4 connector.