Engineering Documentation

Table Of Contents
Chapter 2 Network Electrical Systems
RS-485 ALN (P2/P3) and FLN (P1) Trunk Communications Wiring
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RS-485 FLN (P1) Trunk Shield Connection
NOTE:
The symbol ( ), is the symbol being used to represent RS-485 communications
common reference.
Early versions of some controllers may show the earth ground symbol ( ) or the
"S" designation.
FLN trunk terminal "S" is not grounded or connected to the equipment controller case.
It is used only to tie shields together. The Figure FLN P1 Trunk Connection to TEC
Electronic Output shows how the FLN trunk is connected to electronic output Terminal
Equipment Controllers.
Fig. 23: RS-485 FLN (P1) Trunk Shield Connection—Electronic Output.
* Field Panel Notes (FP begins shield earth ground)
1.
MBC, SCU & FLNC: connect shield to FLN “S” pin; earth ground is internally connected.
2.
MEC: connect “E” pin to enclosure earth ground or Service Box “E” pin and connect shield to FLN “S” pin.
3.
PXC-M & PXC-C: connect ( ) and shield to enclosure earth ground and leave FLN “S” pin unconnected.
4.
When FLN Speed is set greater than 4800 bps use Trunk Terminator (538-664) at both ends of trunk wire. .
FLN Device Notes (shield is continuous from FP or tied back and earth ground restarted; if present connect Earth Ground).
5.
TEC/ATEC: tie both shields to “S” pin and if required connect transformer neutral to earth ground; do not earth ground “N” pin.
6.
N-VARIANT TEC/ATEC: tie both shields together and do not connect to controller leaving unconnected. Connect transformer
neutral to earth ground; if needed earth ground “E” pin to provide highest noise immunity.
7.
UC: **bypass “S” pin or restart shield on “S” pin; connect “E” pin to enclosure earth ground.
8.
DPU: tie both shields to “S” pin; earth ground is internally connected.
9.
P1-BIM: leave “S” pin open - **bypass or restart shield on enclosure earth ground; connect (peg sym) to enclosure earth ground.
10.
MPU: **bypass “S” pin or restart shield on “S” pin; connect “G” pin to enclosure earth ground.
11.
PXM: **bypass “S” pin or restart shield on “S” pin; connect “E” pin to enclosure earth ground.
12.
PPM: leave “S” pin open - **bypass or restart shield on enclosure earth ground; connect (peg sym) to enclosure earth ground.
13.
P1-PXC: leave “S” pin open - **bypass or restart shield on enclosure earth ground; connect (peg sym) to enclosure earth ground.