Wiring Considerations - Allen-Bradley SLC 500 1746-NI4 Installation Instruction

Wiring Considerations

The following section provides system wiring guidelines, how to ground your
Belden™ cable, and how to determine the cable length.
ATTENTION
!
System Wiring Guidelines
Use the following guidelines in planning the system wiring for the analog
modules:
• all analog common terminals (ANL COM) are electrically connected inside
the module. ANL COM is not connected to earth ground inside the module.
• voltages on IN+ and IN- terminals must remain within ± 20 Volts with respect
to ANL COM to ensure proper input channel operation. This is true for current
and voltage input channel operation.
• voltage outputs (OUT 0 and OUT 1) of the NIO4V and NO4V are referenced
to ANL COM. Load resistance (R1) for a voltage output channel must be
greater than or equal to 1K ohms.
• current output channels (OUT 0 and OUT 1) of the NIO4I and NO4I source
current that returns to ANL COM. Load resistance (R1) for a current output
channel must remain between 0 and 500 ohms.
After the analog input module is properly installed in the chassis, follow the
wiring procedure below using Belden 8761 cable.
ATTENTION
!
Before wiring any analog module, disconnect power from the
SLC 500 system and from any other source to the analog
module.
Care should be taken to avoid connecting a voltage source to a
channel configured for current input. Improper module
operation or damage to the voltage source can occur.
SLC 500™ Analog I/O Modules
Publication 1746-IN008A-US-P
13