IBM Series 1 User Manual page 193

DPC ADAPTER ELECTRICAL CHARACTERISTICS
The
ope
adapter drivers and terminators are designed to
interface
with
cables that have a characteristic impedance
of approximately 100 ohms.
All
OPC adapter interface lines are down level active.
The interface is non-isolated, TTL compatible.
Figure 6-5 shows the output signal electrical circuit.
The
output specifications are as follows:
Driver type:
output
voltage:
Input current:
TTL open collector
Up level: +2.4 volts minimum
Down level: +0.7 volts maximum
Q)
175 mA
Maximum current sinking capacity, 175 mA
Q}
+0.1 volts
Figure 6-6 shows the input signal electrical circuit. The
input specifications are as follows:
Input vol tage:
Input current:
Input impedance:
Logic one:
Logic zero:
6-12 GA34-0033
Down level: +0.6 volts
maximum
w
42 rnA
Up level: +2.4 volts minimum
~ 42 mA
Q)
+ 0.6 volts
100 ohms
5 +1.0 volts
~ +2.5 volts
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