Rockwell Automation 1756-XXXX ControlLogix Analog I/O Modules - Manual (Page 175)

Publication 1756-UM009C-EN-P - December 2010 175
Isolated Analog Output Modules (1756-OF6CI and 1756-OF6VI) Chapter 8
For loads under 550
Ω
, the module’s +13V internal voltage source can supply
voltage for currents up to 21 mA. For loads over 550
Ω
, additional compliance
voltage is required. In this case, you must use the ALT terminal to provide the
additional -13V source.
For any size load (that is, 0…1000
Ω
), the output channels function if
terminated between OUT-x and ALT-x. To improve module reliability and
product life, we recommend you:
• Terminate the output channels between the OUT-x and RTN-x
terminals for loads of 0…550
Ω
• Terminate the output channels between the OUT-x and ALT-x
terminals for loads of 551…1000
Ω
.
IMPORTANT
If you are unsure of the load, you can terminate the output
channels between OUT-x and ALT-x and the module will operate
but reliability may be compromised at elevated temperatures.
For example, if you terminate the output channels between
OUT-x and ALT-x and use a 250
Ω
load, the module operates but
the lower load results in higher operating temperatures and
may affect the module’s reliability over time.
We recommend you terminate the output channels as described
above whenever possible.