Measurement Computing PCM-D24/CTR3 rev.3 - Manual (Page 23)

8 SPECIFICATIONS
Typical for 25°C unless otherwise specified.
8.1 POWER CONSUMPTION
+5V (normal operation) 47mA typical, 65mA max
+5V (during CIS read) 62 mA typical, 80 mA max
8.2 DIGITAL I/O
Digital Type MSM82C55
Configuration 2 banks of 8, 2 banks of 4, programmable by bank as input
or output
Number of channels 24 I/O
Output High 3.7 volts min @ -2.5mA
Output Low 0.4 volts max @ 2.5mA
Input High 2.2 volts min, 5.5 volts absolute max
Input Low 0.8 volts max, -0.5 volts absolute min
Power-up / reset state Input mode (high impedance)
Interrupts Programmable levels 2 - 15
Interrupt enable Programmable
Interrupt sources Programmable: external (Ext Int) or internal (counter 0
output, counter 1 output, counter 2 output, 8255 port C0 or
8255 port C3)
8.3 COUNTERS
Counter type 82C54
Configuration 3 down counters, 16 bits each
Counter 0 - Independent user counter 1
Source: Programmable internal 10MHz or external
(CTR 1 Clk)
Gate: External (CTR 1 Gate), pulled high (enabled) by
10k resistor
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