Figure 8: Maximum wire length for low-voltage
(<30 V) Inputs and Outputs by current and wire size
Communications bus and supply power wiring guidelines
Table 5 provides information about the functions, ratings, and requirements for the communication
bus and supply power terminals. The table also provides guidelines for wire sizes, cable types, and
cable lengths for when you wire the controller's communication buses and supply power.
In addition to the guidelines in Table 5, observe these guidelines when you wire an SA or FC bus
and the 24 VAC supply power:
• Run all low-voltage wiring and cables separate from high-voltage wiring.
• All SA and FC bus cables, regardless of wire size, should be twisted, insulated, stranded copper
wire.
• Shielded cable is strongly recommended for all SA and FC bus cables.
• Refer to the following documents depending on your system (FX or BCPro):
MS/TP
Communications Bus for the BCPro™ System Technical Bulletin (LIT-12011908)
or
FX-PC Series
Controllers MS/TP Communications Bus Technical Bulletin (LIT-12011670)
for detailed information
regarding wire size and cable length requirements for SA and FC buses.
Communications bus and supply power terminal block
Note:
The SA Bus and FC Bus wiring recommendations in this table are for MS/TP bus
communications at 38.4k baud. For more information, refer to the following documents
depending on your system (FX or BCPro):
MS/TP Communications Bus for the BCPro System
Technical Bulletin (LIT-12011908)
or
FX-PC Series Controllers MS/TP Communications Bus Technical
Bulletin (LIT-12011670)
.
PCA3613 Advanced Application Programmable Controller Installation Instructions
20
