Connecting Digital Signals; Connecting Counter/Timer I/O Signals - Keithley DAS-800 series User Manual

Connecting Digital Signals

Connecting Counter/Timer I/O Signals

4-12
You can connect the following digital signals to a DAS-800 Series board:
Digital input signal - Connect a digital input signal to the IP1 /
G
TRIG, IP2, or IP3 pin (pin 25, 26, or 27) on the main I/O connector.
Digital output signal - Connect a digital output signal to the OP1,
G
OP2, OP3, or OP4 pin (pin 7, 8, 9, or 10) on the main I/O connector.
External conversion clock - Connect an external conversion clock to
G
the INT_IN / XCLK pin (pin 24) on the main I/O connector.
Hardware digital trigger or hardware gate - Connect a hardware
G
digital trigger or hardware gate signal to the IP1 / TRIG pin (pin 25)
on the main I/O connector.
External interrupt - Connect an external interrupt to the INT_IN /
G
XCLK pin (pin 24) on the main I/O connector.
Make sure that all digital signals are TTL-level compatible. Use the
digital common as the return for all digital signals.
To prevent damage to DAS-800 Series boards, do not apply
Caution:
voltages exceeding TTL maximum levels (
input pins.
Refer to 8254 documentation for information on connecting counter/timer
I/O signals to the clock input pin, gate input pin, and output pin of any
available counter/timers on a DAS-800 Series board. Table 2-2 on page
2-25 lists several companies that provide documentation for the 8254.
To cascade counter C/T2 to counter C/T1 — when C/T0, C/T1,
Note:
and C/T2 are available for general-purpose tasks — externally wire the
output of counter C/T2 (OUT2, pin 6 of the main connector) to the clock
input of counter C/T1 (CLK1, pin 4 of the main connector).
−
0.5 V to +5.5 V) to digital
Cabling and Wiring