Data Translation DT9820 Series, User Manual

Page: 39 / 112

Principles of Operation
27
2
2
2
2
2
2
2
2
2
Note:
+5 V output is available only when one of the subsystems is
activated, which, in turn, activates power to the module.
Resolution
The resolution of the digital input port is fixed at 8; the resolution of
the digital output port is also fixed at 8.
Operation Modes
The DT9820 Series function modules support the single-value digital
I/O operation mode.
Use software to specify the digital I/O port and a gain of 1 (the gain is
ignored). Data is then read from or written to the digital I/O lines.
For a single-value operation, you cannot specify a clock or trigger
source.
Single-value operations stop automatically when finished; you
cannot stop a single-value operation.
Note: All the digital inputs must be in the high state before the
DT9820 Series module can detect a high-to-low transition on the
digital input lines. Therefore, if you are using the digital inputs to
trigger the A/D subsystems, it is recommended that you do not
perform a single-value operation on the DIN subsystem.