Rockwell Automation 1734-IA2, User Manual

Page: 115 / 242

Publication 1734-UM001D-EN-P - April 2008
POINT I/O Module Data 113
Operational Modes
The 1734-OE2C module has these modes:
•
0…20 mA
•
4…20 mA (Default mode)
The 1734-OE2V module has these modes:
•
0… 10V dc (Default mode)
•
-10…10V dc
You can set Channel Mode individually. The effective difference in the two
modes is how you apply the scalers. There is no internal offset, meaning that
the resolution is not changed.
For the 1734-OE2C module, in both modes, you assign the high scaler the
value of 20 mA. For the low scaler you assign the following:
•
In 0…20 mA mode, the value of 0 mA
•
In 4… 20 mA mode, the value of 4 mA
For the 1734-OE2V module, in both modes, you assign the high scaler the
value of +10V. For the lower scaler you assign the following:
•
In 0…10V mode, the value of 0V
•
In +10V mode, the value of -10V
Scaling
Scaling is the conversion of unscaled data to Engineering Units. The high and
low scalers (Engineering Units) are Signed Integers. There are no restrictions
on these units.
Default scaling points are 1638 @ 4 mA and 8191 @ 20 mA counts for the
1734-OE2C module and 0 and 10,000 for the 1734-OE2V module. Each
scaler can be set individually and on a per-channel basis.
The 1734-OE2C module calculates and outputs a current between
0 mA or 4 mA (low scaler) and 20 mA (high scaler); the 1734-OE2V module
calculates and outputs a voltage between -10V or 0V (low scaler) and +10V
(high scaler).