Measurement Computing WBK40 - Manual (Page 32)

Front Panel – Digital I/O Characteristics:
Note: The following characteristics apply to the16 Digital I/O lines that connect
to the front panel’s removable screw-terminal blocks.
Output Driver:
Resistor & Pull-up: 100
Ω series resistor with a 10 KΩ pull-up to 5 V
Current: source 12 mA; sink 12 mA
Output Voltage:
High Level: 2.5 V min @ 12 mA
Low Level: 0.5 V min @ 4 mA
Input Voltage: valid range of - 0.3 V to + 5.0 V
Frequency/Pulse Counters
Counter inputs can be scanned synchronously along with analog and digital scanned inputs, based either on
internal programmable timer, or an external clock source. Counters can be configured to clear when read, or to
totalize and clear under program control.
Channels: 4 x 16-bit; cascadable as 2 x 32-bit
Frequency Measurement Rate: 10 MHz max
Input Signal Range: -15V to +15V
Trigger Level: TTL
Minimum Pulse Width: 50 ns high, 50 ns low
Frequency/Pulse Generators
Channels: 2 x 16-bit
Output Waveform: Square wave
Output Rate: 1 MHz base rate divided by 1 to 65535 (programmable)
High-Level Output Voltage: 2.0V min @ -3.75 mA; 3.0V min @ -2.5 mA
Low-Level Output Voltage: 0.4V max @ 2.5 mA
pg. 32, WBK40 & WBK41 926896 Thermocouple and Multifunctional Modules