Rockwell Automation 1769-OF4 Compact Analog Output Module - Manual (Page 23)

Publication 1769-UM020A-EN-P - December 2009 23
Installation and Wiring Chapter 2
As output impedance (Rs) and/or resistance (DC) of the cable (Rc) get
larger, system accuracy decreases. If you determine that the
inaccuracy error is significant, implementing the following equation in
the control program can compensate for the added inaccuracy error
due to the impedance of the module’s voltage outputs and cable.
Label the Terminals A removable, write-on label is provided with the module. Remove the
label from the door, mark the identification of each terminal with
permanent ink, and slide the label back into the door. Your markings
(ID tag) will be visible when the module door is closed.
Remove the Finger-safe
Terminal Block When wiring field devices to the module, it is not necessary to remove
the terminal block. If you remove the terminal block, use the write-on
label on the side of the terminal block to identify the module slot
location and type. RTB position (for one-and-a-half size modules) can
be indicated by circling either the R for right side or L for left side.
Finger-safe Terminal Block
To remove the terminal block, loosen the upper and lower retaining
screws. The terminal block will back away from the module as you
remove the screws. When replacing the terminal block, torque the
retaining screws to 0.46 N•m (4.1 lb•in).
TIP
For current outputs, source and cable impedance do not impact
system accuracy as long as the total resistance of the cable and
input impedance of the load remain within the specified
maximum limits for the module's current outputs.
Vs Vin
Rs 2 Rc
× ( )
Ri + +
[ ]
Ri
--------------------------------------------------------
×
=
SLOT # ____
MODULE TYPE _____
R L
RoHS