Measurement Computing StrainBook/616 - Manual (Page 97)

Digital I/O, TTL Trigger, and External Clock 8
Introduction …… 8-1
Connections for 16-Bit Mode …… 8-1
Connections for 8-Bit Mode …… 8-2
TTL Trigger …… 8-3
External Clock …… 8-3
Introduction
This brief chapter exists primarily to indicate how Digital I/O connections are made for both the 16-bit and
8-bit Digital I/O modes. WaveView uses the 16-bit mode.
Connections for 16-Bit Mode
For 16-bit mode, the following signals are present on the StrainBook’s DB25F high-speed digital I/O
connector. Note that 8-bit mode is covered in the following section.
o 16 High-Speed Digital I/O Lines (D0 through D15)
o TTL Trigger Input (TTLTRG)
o +15 V (pin 23), -15 V (pin 22), 50 mA max. (each)
o two +5 V (pin 19 and pin 21), 250 mA max. (total)
o External Clock Input (pin 20)
o Digital Clock (pin 18), only used for WBK17 applications
o two Digital Grounds (pins 24 and 25)
To sample 16 digital input signals, connect them directly to the digital I/O data lines as indicated below.
D15 is the most significant bit, and D0 is the least. WaveView is pre-set to use the 16-bit mode.
Digital I/O Connections, 16-Bit Mode
D0 through D15 High Speed Digital I/O data
lines
TTLTRG TTL trigger input
External Clock
Input
16 bit mode, read/write strobe,
Pin 20
+5 VDC 250 mA maximum
+15,-15 VDC 50 mA maximum (each)
Digital Clock Pin 18, only used for WBK17
applications
Digital Grounds Pins 24 and25
DB25 Pinout, 16-Bit Mode
StrainBook/616 977794 Digital I/O, TTL Trigger, and External Clock 8-1