Measurement Computing IOtech 640 Series - Manual (Page 53)

640 & 650 Series 878893 Digital I/O 7-1
Digital I/O 7
Applies only to eZ-TOMAS and eZ-NDT
Digital Inputs and Outputs
Eight digital I/O lines are included in each of the 600 series modules, accessible via a 9-pin, female DSub
connector. Each bit of digital I/O can be programmed individually to be either an input or an output. By hardware
default, the digital I/O port boots up as an input. This is to prevent any output of the 600 series device from
damaging external customer hardware.
640u Rear Panel with DB9 Connector for Digital I/O
All 640/650 Series units have a DB9 connector centrally
located on their rear panel.
DB9 – As viewed from the rear panel
Outer numbers are digital channels.
Inner numbers are pin designations.
The digital I/O can be read synchronously or asynchronously. It can also be read asynchronously while being in a
synchronous acquisition. Synchronously, the digital I/O will be read at the same rate as the analog channels, and
thus can be read as fast as 105.469 kHz. Since all of the analog signals are read simultaneously along with the
digital I/O channel in synchronous mode, there is no delay between any analog signal and the digital I/O channel.
Asynchronously, the digital I/O can be either read or written to, as opposed to the synchronous mode, which is read-
only.
640/650 Digital I/O is only applicable to eZ-TOMAS and eZ-NDT.
Points to note:
• To use 640/650 Series device Digital I/O, either eZ-TOMAS or eZ-NDT software must be used.
• All configurations pertaining to digital I/O are controlled by software and can be updated by the
software at any time.
• All 8 digital inputs can be read back as part of the scan group of an acquisition.
Reference Note:
For detailed documentation regarding software and Digital I/O you will need to refer to one or more
of the following, as applicable. A PDF version of each is included on the installation CD.
¾ eZ-TOMAS User’s Manual
¾ eZ-NDT User’s Manual