Figure 3-6 Rs-422/485 Communications Option Connections; Figure 3-7 Ethernet Communications Option With Adaptor Board - Honeywell 7866 Operation And Maintenance Manual

Installation
4 SHLD
1 Do not run the communications lines in the same conduit as AC power.
2 Use shielded twisted pair cables (Belden 9271 Twinax or equivalent).
RS-422/485 connections must be "daisy-chained," T-drop connections are not allowed.

Figure 3-7 Ethernet Communications Option with Adaptor Board

Instruments equipped with the Ethernet Communications Option come with an Ethernet Adaptor Kit. To
use this kit, first remove the four screws on your instrument from Terminal Block positions 24 through 27.
Place the Ethernet Adaptor Board on to the terminal block as shown and then secure it in place with the
four long screws provided in the kit. Route the long wire on the Ethernet Adaptor Board over to Terminal
#4 on your instrument. The RJ-45 connector on the Ethernet Adaptor Board will allow you to use a
straight-through cable to connect the controller to a MDI Compliant Hub or Switch. Alternatively, you
may use a crossover cable to connect your controller directly to a PC, which is useful for commissioning
purposes. Use only Category 5 (STP CAT5) shielded twisted-pair Ethernet cables. For strain relief, secure
your Ethernet cable to the controller with the tie wraps included in the kit using the holes in the bottom
controller flange.
30 7866 Triple Range Digital H
UDC3500
SHLD
26 D+ (B)
D+
27 D– (A)
D–
TO OTHER
COMMUNICATION
CONTROLLERS
D–
120 OHMS ON LAST LEG

Figure 3-6 RS-422/485 Communications Option Connections

10
11
L1
12
L2/N
13
4
14
5
15
6
16
7
17
8
9
18
Tie Wraps (2)
and CO
2 2
COMMUNICATION MASTER
D+ (B) SHLD D– (A)
1 2
120 OHMS
Connect shield
to ground at one
end only.
D+
28
19
Ethernet
29
20
Adaptor
30
21
31
22
32
23
33
24
Ethernet
Cable To
34
25
Hub or
35
26
36
27
Analyzer/Indicator - Operation and Maintenance
24
27
9/06