Spectrum Controls 1746sc-INO4vi - Manual (Page 39)

Testing Your Module
Read this chapter to prevent potential problems. This chapter covers:
• inspecting your module
• disconnecting prime movers
• powering up
• interpreting the LED indicators
• interpreting I/O error codes
• troubleshooting
Before testing your module, test your SLC 500 system using the
procedures described in your Allen-Bradley system Installation &
Operation Manual.
Important — If your module appears to be functioning, but the
terminals aren’t providing an output signal, the 24 Vdc power source
(backplane or external) may not be providing enough current (250 mA).
Inspecting Your Module You can prevent many potential problems by simply inspecting your
analog module:
1. Ensure that the external 24 Vdc power switch (SW1, located in the
bottom corner of the module’s large circuit board) is set properly:
• With the switch in the RACK position, the module draws all its
power from the backplane of the SLC system.
• With the switch in the EXT position, the module draws its 24 Vdc
power from an external power source; however, the module still
draws its 5 Vdc power from the backplane.
2. Ensure that all wire connections are correct and secure and that no
wires are missing or broken. Refer to Chapter 2, Installing And Wiring
Your Module, for more information.
3. Ensure that the shield for the cable used to wire your module is
properly grounded.
4. Ensure that the removable terminal block on your module is secure.
Chapter 5